The Hall ratio conjecture… to Moments of the Riemann zeta…
TheoremThe Hall ratio conjecture (Harris 2019) — disproved#
References: * [Ha19] Harris, D. G. (2019). "Some results on chromatic number as a function of triangle count." SIAM J. Discrete Math. 33, pp. 546--563. * [DOW20] Dvořák, Z., Ossona de Mendez, P. and Wu, H. (2020). "1-subdivisions, the fractional chromatic number and the Hall ratio." Combinatorica 40, pp. 759--774. arXiv:1812.07327 * [BLMNPV22] Blumenthal, A., Lidický, B., Martin, R. R., Norin, S., Pfender, F. and Volec, J. (2022). "Counterexamples to a conjecture of Harris on Hall ratio." SIAM J. Discrete Math. 36, pp. 1678--1686. arXiv:1811.11116 * [SU97] Scheinerman, E. R. and Ullman, D. H. (1997). Fractional Graph Theory. Wiley.
Quoted from FormalConjectures/Paper/HallRatioConjecture.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 3 research or textbook statements: 3 solved.
HallRatioConjecture.hall_ratio_conjecture
Solved: stated here without proof.
The Hall ratio conjecture (Harris 2019) — disproved.
Harris conjectured that the fractional chromatic number is bounded by a constant multiple of the Hall ratio: there is a constant \(C\) with \(\chi_f(G) \le C\,\rho(G)\) for every graph \(G\). This is false: Dvořák, Ossona de Mendez and Wu [DOW20] and, independently, Blumenthal, Lidický, Martin, Norin, Pfender and Volec [BLMNPV22] constructed graphs with \(\chi_f / \rho\) arbitrarily large.
theorem hall_ratio_conjecture : ¬
∃ C : ℝ, ∀ {V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V),
G.fractionalChromaticNumber ≤ C * hallRatio G
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/HallRatioConjecture.lean, line 60.
HallRatioConjecture.hall_ratio_conjecture.variants.hallRatio_le_fractionalChromaticNumber
Solved: stated here without proof.
The Hall ratio is a lower bound for the fractional chromatic number.
For every graph, \(\rho(G) \le \chi_f(G)\) (see [SU97]); the conjecture asked for an inequality in the other direction up to a constant.
theorem hall_ratio_conjecture.variants.hallRatio_le_fractionalChromaticNumber
{V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V) :
hallRatio G ≤ G.fractionalChromaticNumber
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/HallRatioConjecture.lean, line 72.
HallRatioConjecture.hall_ratio_conjecture.variants.unbounded
Solved: stated here without proof.
Unbounded ratio (Dvořák–Ossona de Mendez–Wu 2020; Blumenthal et al. 2022).
For every \(C\) there is a graph with \(\chi_f(G) > C\,\rho(G)\).
References: [DOW20], [BLMNPV22].
theorem hall_ratio_conjecture.variants.unbounded (C : ℝ) :
∃ (V : Type) (_ : Fintype V) (_ : DecidableEq V) (G : SimpleGraph V),
C * hallRatio G < G.fractionalChromaticNumber
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/HallRatioConjecture.lean, line 85.
Sources
TheoremHartshorne's conjecture on Vector Bundles#
References: * [Har1974] R. Hartshorne, Varieties of small codimension in projective space. * [MO2010] Evidences on Hartshorne's conjecture? References?
Quoted from FormalConjectures/Paper/HartshorneConjecture.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 1 research or textbook statement: 1 open. It also has 1 API statement, counted here but not shown.
AlgebraicGeometry.Scheme.harthshorne_conjecture
Open: stated without proof.
There are no indecomposable vector bundles of rank 2 on \(\mathbb{P}^n\) for \(n \ge 7\). This is Conjecture 6.3 in [Har1974].
theorem harthshorne_conjecture (n : ℕ) (hn : 7 ≤ n)
(𝓕 : VectorBundles ℙ(Fin (n + 1); Spec (.of ℂ)))
(h𝓕 : 𝓕.rank = 2) :
Nonempty (𝓕.Splitting (Fin 2))
Category research open; AMS 14 Algebraic geometry. Declared in FormalConjectures/Paper/HartshorneConjecture.lean, line 85.
Sources
TheoremConjectures around homogeneous topological spaces#
This file formalizes the notions of a homogeneous topological space and of (ω-)monolithic topological spaces, and states some open problems about homogeneous and monolithic compact spaces.
References: * [Ar2013] Arhangeliski, Alexandr. "Selected old open problems in general topology." Buletinul Academiei de Ştiinţe a Republicii Moldova. Matematica 73.2-3 (2013): 37-46. https://www.math.md/files/basm/y2013-n2-3/y2013-n2-3-(pp37-46).pdf.pdf * [Ar1987] Arhangel'skii, A. V. "Topological homogeneity. Topological groups and their continuous images." Russian Mathematical Surveys 42.2 (1987): 83-131. https://doi.org/10.1070/RM1987v042n02ABEH001333
Quoted from FormalConjectures/Paper/Homogenous.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 5 research or textbook statements: 5 open. It also has 5 test statements, counted here but not shown.
Homogeneous.homogeneousSpace_exists_inj_tendsto
Open: stated without proof.
Problem 13 in [Ar2013]: Is it true that every infinite homogeneous compact hausdorff space contains a non-trivial convergent sequence?
theorem homogeneousSpace_exists_inj_tendsto :
∀ (X : Type) (_ : TopologicalSpace X), ¬ Finite X → T2Space X → CompactSpace X →
HomogeneousSpace X → ∃ s : ℕ → X, s.Injective ∧ ∃ a : X, Tendsto s atTop (nhds a)
Category research open; AMS 54 General topology. Declared in FormalConjectures/Paper/Homogenous.lean, line 63.
Homogeneous.homogeneousSpace_exists_surjective
Open: stated without proof.
Problem 14 in [Ar2013]: Is it possible to represent an arbitrary compact hausdorff space as an image of a homogeneous compact space under a continuous mapping?
theorem homogeneousSpace_exists_surjective :
∀ (X : Type) (_ : TopologicalSpace X), T2Space X → CompactSpace X →
∃ (Y : Type) (_ : TopologicalSpace Y), T2Space Y ∧ CompactSpace Y ∧ HomogeneousSpace Y ∧
∃ f : Y → X, Continuous f ∧ f.Surjective
Category research open; AMS 54 General topology. Declared in FormalConjectures/Paper/Homogenous.lean, line 72.
Homogeneous.firstCountableTopology_of_countablyMonolithicSpace
Open: stated without proof.
Problem 15 in [Ar2013]: Is every homogeneous ω-monolithic compact hausdorff space first countable?
theorem firstCountableTopology_of_countablyMonolithicSpace :
∀ (X : Type) (_ : TopologicalSpace X), T2Space X → CompactSpace X →
HomogeneousSpace X → CountablyMonolithicSpace X → FirstCountableTopology X
Category research open; AMS 54 General topology. Declared in FormalConjectures/Paper/Homogenous.lean, line 94.
Homogeneous.countablyMonolithicSpace_card_lt
Open: stated without proof.
Problem 16 in [Ar2013]: Is the cardinality of every homogeneous ω-monolithic compact hausdorff space not greater than 𝔠?
theorem countablyMonolithicSpace_card_lt :
∀ (X : Type) (_ : TopologicalSpace X), T2Space X → CompactSpace X →
HomogeneousSpace X → CountablyMonolithicSpace X → #X ≤ 𝔠
Category research open; AMS 54 General topology. Declared in FormalConjectures/Paper/Homogenous.lean, line 102.
Homogeneous.monolithicSpace_exists_nhds_generated_countable
Open: stated without proof.
Problem 17 in [Ar2013]: Is it true that every nonempty monolithic compact hausdorff space contains a point with a first countable neighborhood basis?
Note:
Nonempty Xis required since the conclusion asserts the existence of a point.
theorem monolithicSpace_exists_nhds_generated_countable :
∀ (X : Type) (_ : TopologicalSpace X), T2Space X → CompactSpace X →
Nonempty X → MonolithicSpace X → ∃ x : X, (𝓝 x).IsCountablyGenerated
Category research open; AMS 54 General topology. Declared in FormalConjectures/Paper/Homogenous.lean, line 152.
Sources
TheoremKaplansky's problem on the values of the \(u\)-invariant#
The \(u\)-invariant \(u(F)\) of a field \(F\) is the largest dimension of an anisotropic quadratic form over \(F\), or \(\infty\) if there is no largest one; that is, \(u(F) = n\) exactly when
IsGreatest (QuadraticForm.anisotropicDims F) n. Following [Kaplansky1953] and [MerkurjevParimala2025, §5.1], all fields are of characteristic not \(2\).Kaplansky introduced the invariant (his \(C(F)\)) in [Kaplansky1953, p. 201], proved that \(u(F) \ne 3\) (his Theorem 2), observed that every power of \(2\) occurs (his Theorem 3 gives \(u(F((t))) = 2u(F)\)), and conjectured that \(u(F)\) is a power of \(2\) whenever it is finite [Kaplansky1953, p. 202]. It is classical that \(u(F) \notin \{3, 5, 7\}\) [Lam2005, Proposition XI.6.8], [EKM2008, Corollary 36.4]. Merkurjev disproved Kaplansky's conjecture with a field of \(u\)-invariant \(6\) [Merkurjev1989] and then showed that every positive even integer is a \(u\)-invariant [Merkurjev1991]. Izhboldin constructed a field of \(u\)-invariant \(9\) [Izhboldin2001], and Vishik fields of \(u\)-invariant \(2^r + 1\) for every \(r \ge 3\) [Vishik2009]. A 2026 preprint of Karpenko constructs fields of \(u\)-invariant \(n\) for every \(n\) that is neither of the form \(2^r - 1\) nor of the form \(2^r - 3\) [Karpenko2026]; as of September 2026 it is not yet peer-reviewed.
The problem (
u_invariant_values) is to determine which integers are \(u\)-invariants of fields. The survey [MerkurjevParimala2025, §5.1] records the expectation that every odd integer \(\ge 9\) is a \(u\)-invariant (u_invariant_values.variants.odd). Given the results above, the problem is open exactly for the integers \(2^r - 1\) and \(2^r - 3\) with \(r \ge 4\), the smallest of which are \(13\) and \(15\).References: - [Kaplansky1953] I. Kaplansky, Quadratic forms, J. Math. Soc. Japan 5 (1953), 200–207, doi:10.2969/jmsj/00520200. - [Lam2005] T. Y. Lam, Introduction to quadratic forms over fields, Grad. Stud. Math. 67, Amer. Math. Soc., 2005, doi:10.1090/gsm/067. - [EKM2008] R. Elman, N. Karpenko, A. Merkurjev, The algebraic and geometric theory of quadratic forms, Amer. Math. Soc. Colloq. Publ. 56, Amer. Math. Soc., 2008, doi:10.1090/coll/056. - [Merkurjev1989] A. S. Merkurjev, Kaplansky's conjecture in the theory of quadratic forms (Russian), Zap. Nauchn. Sem. LOMI 175 (1989), 75–89; English transl. J. Soviet Math. 57 (1991), no. 6, 3489–3497, doi:10.1007/BF01100118. - [Merkurjev1991] A. S. Merkurjev, Simple algebras and quadratic forms (Russian), Izv. Akad. Nauk SSSR Ser. Mat. 55 (1991), no. 1, 218–224; English transl. Math. USSR-Izv. 38 (1992), no. 1, 215–221, doi:10.1070/IM1992v038n01ABEH002195. - [Izhboldin2001] O. T. Izhboldin, Fields of \(u\)-invariant \(9\), Ann. of Math. (2) 154 (2001), no. 3, 529–587, doi:10.2307/3062141. - [Vishik2009] A. Vishik, Fields of \(u\)-invariant \(2^r + 1\), pp. 661–685 in Algebra, arithmetic, and geometry: in honor of Yu. I. Manin, Vol. II, Progr. Math. 270, Birkhäuser, 2009, doi:10.1007/978-0-8176-4747-6_22. - [Karpenko2026] N. A. Karpenko, Fields of any \(u\)-invariant but a 2-power minus 1 or 3, preprint, 5 August 2026, author's web page. - [MerkurjevParimala2025] A. Merkurjev, R. Parimala, Quadratic forms beyond arithmetic, Notices Amer. Math. Soc. 72 (2025), no. 7, 711–718, doi:10.1090/noti3192.
Quoted from FormalConjectures/Paper/KaplanskyUInvariant.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 14 research or textbook statements: 4 open and 10 solved. It also has 2 test statements, counted here but not shown.
KaplanskyUInvariant.u_invariant_values
Open: stated without proof.
The values of the \(u\)-invariant, stated as in [MerkurjevParimala2025, §5.1]: which integers are \(u\)-invariants of fields (of characteristic not \(2\))? The question goes back to [Kaplansky1953], who conjectured that only powers of \(2\) occur (
u_invariant_values.variants.kaplansky_conjecture). Every positive even integer is a \(u\)-invariant (u_invariant_values.variants.even), \(3\), \(5\) and \(7\) are not (u_invariant_values.variants.not_three,u_invariant_values.variants.not_five,u_invariant_values.variants.not_seven), and it is expected that every odd integer \(\ge 9\) is (u_invariant_values.variants.odd). Granting the preprint [Karpenko2026] (u_invariant_values.variants.karpenko), the answer is known for every \(n\) except \(n = 2^r - 1\) and \(n = 2^r - 3\) with \(r \ge 4\).
theorem u_invariant_values :
∀ n, n ∈ u_invariant_values.answer ↔ IsUInvariant n
Category research open; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 136.
KaplanskyUInvariant.u_invariant_values.variants.kaplansky_conjecture
Solved: stated here without proof.
Kaplansky's conjecture [Kaplansky1953, p. 202]: the \(u\)-invariant of a field is a power of \(2\) whenever it is finite. Disproved by Merkurjev, who constructed a field of \(u\)-invariant \(6\) [Merkurjev1989] (
u_invariant_values.variants.even).
theorem u_invariant_values.variants.kaplansky_conjecture :
¬ ∀ n, IsUInvariant n → ∃ k, n = 2 ^ k
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 146.
KaplanskyUInvariant.u_invariant_values.variants.not_three
Solved: stated here without proof.
The \(u\)-invariant is never \(3\) [Kaplansky1953, Theorem 2]; see also [Lam2005, Proposition XI.6.8] and [EKM2008, Corollary 36.4].
theorem u_invariant_values.variants.not_three : ¬ IsUInvariant 3
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 153.
KaplanskyUInvariant.u_invariant_values.variants.not_five
Solved: stated here without proof.
The \(u\)-invariant is never \(5\) [Lam2005, Proposition XI.6.8], [EKM2008, Corollary 36.4].
theorem u_invariant_values.variants.not_five : ¬ IsUInvariant 5
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 158.
KaplanskyUInvariant.u_invariant_values.variants.not_seven
Solved: stated here without proof.
The \(u\)-invariant is never \(7\) [Lam2005, Proposition XI.6.8], [EKM2008, Corollary 36.4].
theorem u_invariant_values.variants.not_seven : ¬ IsUInvariant 7
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 163.
KaplanskyUInvariant.u_invariant_values.variants.two_pow
Solved: stated here; a Lean proof is at https://github.com/anatoliiohorodnyk/lean-fc-proofs/blob/47cc44ab944b6fd29b98a256ed4f92c8316f86bf/Proofs/T_KaplanskyUInvariant_u_invariant_values_variants_two_pow.lean#L563.
Every power of \(2\) is a \(u\)-invariant [Kaplansky1953, p. 202]: Theorem 3 of [Kaplansky1953] gives \(u(F((t))) = 2u(F)\), so \(u(\mathbb{C}((t_1)) \cdots ((t_k))) = 2^k\); see also [EKM2008, §38].
theorem u_invariant_values.variants.two_pow (k : ℕ) : IsUInvariant (2 ^ k)
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 173.
KaplanskyUInvariant.u_invariant_values.variants.even
Solved: stated here without proof.
Merkurjev's theorem [Merkurjev1991], see also [EKM2008, Theorem 38.4]: every positive even integer is a \(u\)-invariant. The case \(6\), the first counterexample to Kaplansky's conjecture, is [Merkurjev1989].
theorem u_invariant_values.variants.even (n : ℕ) (hn : Even n) (hn₀ : n ≠ 0) :
IsUInvariant n
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 182.
KaplanskyUInvariant.u_invariant_values.variants.nine
Solved: stated here without proof.
Izhboldin's theorem [Izhboldin2001]: there is a field of \(u\)-invariant \(9\), the first example of an odd \(u\)-invariant greater than \(1\).
theorem u_invariant_values.variants.nine : IsUInvariant 9
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 189.
KaplanskyUInvariant.u_invariant_values.variants.two_pow_add_one
Solved: stated here without proof.
Vishik's theorem [Vishik2009, Corollary 5.2]: for every \(r \ge 3\) there is a field of \(u\)-invariant \(2^r + 1\).
theorem u_invariant_values.variants.two_pow_add_one (r : ℕ) (hr : 3 ≤ r) :
IsUInvariant (2 ^ r + 1)
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 195.
KaplanskyUInvariant.u_invariant_values.variants.karpenko
Solved: stated here without proof.
Karpenko's theorem [Karpenko2026, Theorem 1.1]: if neither \(n + 1\) nor \(n + 3\) is a power of \(2\), then there is a field of \(u\)-invariant \(n\). This covers every positive integer except \(1\), \(3\), \(5\), \(7\) and the integers \(2^r - 1\), \(2^r - 3\) with \(r \ge 4\). As of September 2026 the result is a preprint and not yet peer-reviewed.
theorem u_invariant_values.variants.karpenko (n : ℕ) (h₁ : ∀ r, 2 ^ r ≠ n + 1)
(h₃ : ∀ r, 2 ^ r ≠ n + 3) : IsUInvariant n
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 206.
KaplanskyUInvariant.u_invariant_values.variants.eleven
Proved here.
The special case \(n = 11\) of
u_invariant_values.variants.karpenko(neither \(12\) nor \(14\) is a power of \(2\)), the first odd value not of the form \(2^r + 1\) shown to be a \(u\)-invariant; it was announced in the preprint Fields of \(u\)-invariant 11 (21 April 2026) that [Karpenko2026] absorbs.
theorem u_invariant_values.variants.eleven : IsUInvariant 11
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 217.
KaplanskyUInvariant.u_invariant_values.variants.odd
Open: stated without proof.
The expectation recorded in [MerkurjevParimala2025, §5.1]: every odd integer \(\ge 9\) is a \(u\)-invariant. By
u_invariant_values.variants.karpenkothis is open exactly for the integers \(2^r - 1\) and \(2^r - 3\) with \(r \ge 4\).
theorem u_invariant_values.variants.odd :
∀ n, Odd n → 9 ≤ n → IsUInvariant n
Category research open; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 230.
KaplanskyUInvariant.u_invariant_values.variants.thirteen
Open: stated without proof.
The smallest open case of the form \(2^r - 3\): is there a field of \(u\)-invariant \(13\)?
theorem u_invariant_values.variants.thirteen : IsUInvariant 13
Category research open; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 236.
KaplanskyUInvariant.u_invariant_values.variants.fifteen
Open: stated without proof.
The smallest open case of the form \(2^r - 1\): is there a field of \(u\)-invariant \(15\)?
theorem u_invariant_values.variants.fifteen : IsUInvariant 15
Category research open; AMS 11 Number theory, 12 Field theory and polynomials. Declared in FormalConjectures/Paper/KaplanskyUInvariant.lean, line 241.
Sources
TheoremKotzig's Conjecture#
Reference: A. Kotzig, cited in A. Rosa, On certain valuations of the vertices of a graph, Theory of Graphs (Internat. Sympos., Rome, 1966), Gordon and Breach, 1967, pp. 349–355.
Kotzig conjectured that for every \(n\), the complete graph \(K_{2n+1}\) decomposes into copies of any \(n\)-edge tree via cyclic shifts of a single embedding. This is strictly stronger than Ringel's conjecture; see
Paper/RingelConjecture.lean. The large-\(n\) case is proved by Montgomery–Pokrovskiy–Sudakov; seeArxiv/2001.02665/RingelConjecture.lean.
Quoted from FormalConjectures/Paper/KotzigConjecture.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 1 research or textbook statement: 1 open.
KotzigConjecture.kotzig_conjecture
Open: stated without proof.
For any tree \(T\) with \(n\) edges, the complete graph \(K_{2n+1}\) decomposes into \(2n+1\) edge-disjoint copies of \(T\) via cyclic shifts of a single embedding.
The \(2n+1\) copies are \(f_0, f_1, \dots, f_{2n}\) where \(f_i(v) = f_0(v) + i\) for all vertices \(v\) — each copy is obtained by adding \(i \pmod{2n+1}\) to every vertex of the base copy. This is strictly stronger than
RingelConjecture.ringel_conjecture.
theorem kotzig_conjecture {V : Type} [Finite V]
(T : SimpleGraph V) (hT : T.IsTree)
(n : ℕ) (hn : T.edgeSet.ncard = n) :
∃ f : Fin (2 * n + 1) → (V ↪ Fin (2 * n + 1)),
(∀ i v, f i v = f 0 v + i) ∧
Pairwise (fun i j => Disjoint (T.map (f i)).edgeSet (T.map (f j)).edgeSet) ∧
⨆ i, T.map (f i) = (⊤ : SimpleGraph (Fin (2 * n + 1)))
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/KotzigConjecture.lean, line 46.
Sources
TheoremKurepa's conjecture#
Reference: On the left factorial function !N, by Đuro Kurepa Math. Balkanica 1, p. 147-153, 1971
Quoted from FormalConjectures/Paper/Kurepa.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 5 research or textbook statements: 3 open and 2 textbook results. It also has 2 test statements, counted here but not shown.
Kurepa.kurepa_conjecture
Open: stated without proof.
Kurepa's conjecture
Kurepa's conjectureFor all \(n\),
\[!n\not\equiv 0 \mod n\]This appears as B44 "Sums of factorials." in Unsolved Problems in Number Theory by Richard K. Guy
theorem kurepa_conjecture (n : ℕ) (h_n : 2 < n) : (!n : ℕ) % n ≠ 0
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/Kurepa.lean, line 50.
Kurepa.kurepa_conjecture.variants.prime
Open: stated without proof.
This statement can be reduced to the prime case only.
theorem kurepa_conjecture.variants.prime (p : ℕ) (h_p : 2 < p) :
p.Prime → (!p : ℕ) % p ≠ 0
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/Kurepa.lean, line 57.
Kurepa.kurepa_conjecture.prime_reduction
Textbook result, proved here.
Kurepa's conjecture for all integers greater than 2 is equivalent to the conjecture restricted to primes greater than 2.
theorem kurepa_conjecture.prime_reduction : (∀ n, 2 < n → (!n : ℕ) % n ≠ 0)
↔ (∀ p, 2 < p → p.Prime → (!p : ℕ) % p ≠ 0)
Category textbook; AMS 11 Number theory. Declared in FormalConjectures/Paper/Kurepa.lean, line 65.
Kurepa.kurepa_conjecture.variants.gcd
Open: stated without proof.
An equivalent formulation in terms of the gcd of \(n!\) and \(!n\).
theorem kurepa_conjecture.variants.gcd (n : ℕ) : 2 < n → (n !).gcd (! n) = 2
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/Kurepa.lean, line 96.
Kurepa.kurepa_conjecture.gcd_reduction
Textbook result, proved here.
Kurepa's conjecture for all integers greater than 2 is equivalent to the statement that \(\gcd(n!, !n) = 2\) for all integers greater than 2.
theorem kurepa_conjecture.gcd_reduction : (∀ n, 2 < n → (!n : ℕ) % n ≠ 0)
↔ (∀ n, 2 < n → (n)!.gcd (!n) = 2)
Category textbook; AMS 11 Number theory. Declared in FormalConjectures/Paper/Kurepa.lean, line 103.
Sources
TheoremConjectures about Latin Squares#
This file formalizes some conjectures and theorems around latin squares.
References: * [Wa2011] Wanless, Ian. "Transversals in Latin Squares: A Survey." Surveys in Combinatorics 2011, R. Chapman, Ed. Cambridge University Press, 2011, pp. 403–437. https://users.monash.edu.au/~iwanless/papers/transurveyBCC.pdf * https://en.wikipedia.org/wiki/Problems_in_Latin_squares
Quoted from FormalConjectures/Paper/LatinSquare.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 10 research or textbook statements: 7 open, 2 solved and 1 textbook result. It also has 2 test statements, counted here but not shown.
LatinSquare.oddOrderLatinSquareTransversal
Open: stated without proof.
Conjecture 3.2 in [Wa2011]: Each Latin square of odd order has at least one transversal.
theorem oddOrderLatinSquareTransversal :
∀ (n : ℕ), Odd n → ∀ (L : LatinSquare n), ∃ σ, IsTransversal L σ
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 60.
LatinSquare.oddOrderLeq9LatinSquareTransversal
Solved: stated here without proof.
The conjecture is known to be true for \(n \leq 9\).
theorem oddOrderLeq9LatinSquareTransversal :
∀ n ≤ 9, Odd n → ∀ (L : LatinSquare n), ∃ σ, IsTransversal L σ
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 68.
LatinSquare.latinSquareOrder11Transversal
Open: stated without proof.
The smallest odd number for which this conjecture is not known is 11.
theorem latinSquareOrder11Transversal :
∀ (L : LatinSquare 11), ∃ σ, IsTransversal L σ
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 76.
LatinSquare.latinSquareNearTransversal
Open: stated without proof.
Conjecture 5.1 in [Wa2011]: Every latin square has a near-transversal
theorem latinSquareNearTransversal :
∀ (n : ℕ) (L : LatinSquare n), ∃ ρ σ, IsNearTransversal L ρ σ
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 91.
LatinSquare.z_even
Textbook result, proved here.
The Cayley table of \(\mathbb{Z}_n\) for positive even \(n\) has no transversals.
theorem z_even (n : ℕ) : z (2 * (n + 1)) = 0
Category textbook; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 118.
LatinSquare.numTransversalsZn
Open: stated without proof.
Conjecture 6.7 in [Wa2011]: There exist real constants \(0 < c_1 < c_2 < 1\) such that
\[ c_1^n n! \leq z_n \leq c_2^n n! \]for all odd \(n \geq 3\).
theorem numTransversalsZn :
∃ᵉ (c₁ > (0 : ℝ)) (c₂ < (1 : ℝ)) (_ : c₁ < c₂),
∀ n ≥ 3, Odd n →
(z n : ℝ) ∈ Set.Icc (c₁ ^ n * n.factorial) (c₂ ^ n * n.factorial)
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 169.
LatinSquare.growthRateZn
Open: stated without proof.
Conjecture 6.9 in [Wa2011]:
\[ \lim_{\substack{n \to \infty \\ n \text{ odd}}} \frac{1}{n} \log(z_n / n!) = -1 \]It is not even known if this limit exists. Note that \(z_n = 0\) for even \(n\) (see
z_even), so the limit must be restricted to odd \(n\); here we parametrise odd \(n\) as \(2k + 1\).
theorem growthRateZn :
Filter.Tendsto (fun k => (1 : ℝ) / (2 * k + 1) *
Real.log (z (2 * k + 1) / (2 * k + 1).factorial)) Filter.atTop
(nhds (-1))
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 184.
LatinSquare.maxTransversalsBound
Solved: stated here without proof.
Theorem 7.2 in [Wa2011]: For all \(n \geq 5\),
\[ 15^{n/5} \leq T(n) \leq c^n \sqrt{n} \cdot n! \]where \(c = \sqrt{\frac{3 - \sqrt{3}}{6}} \cdot e^{\sqrt{3}/6}\)
theorem maxTransversalsBound :
let c := Real.sqrt ((3 - Real.sqrt 3) / 6) * Real.exp (Real.sqrt 3 / 6)
∀ n : ℕ, n ≥ 5 →
(T n : ℝ) ∈ Set.Icc ((15 : ℝ) ^ ((n : ℝ) / 5)) (c ^ n * Real.sqrt n * n.factorial)
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 202.
LatinSquare.molsExistenceProblem
Open: stated without proof.
MOLS existence problem: determine exactly which orders
nadmit a complete set ofn - 1mutually orthogonal latin squares.Equivalently, this asks for which orders affine planes of order
nexist. Complete sets are known for prime-power orders; the smallest currently unresolved order is12.
theorem molsExistenceProblem : molsExistenceProblem.answer = {n : ℕ | HasCompleteMOLS n}
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 218.
LatinSquare.molsOrder12
Open: stated without proof.
The smallest unresolved case of the MOLS existence problem: whether there are
11mutually orthogonal latin squares of order12.
theorem molsOrder12 : HasCompleteMOLS 12
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinSquare.lean, line 226.
Sources
TheoremLatin Tableau Conjecture#
The Latin Tableau Conjecture states that the graph associated to any (finite) Young diagram (i.e., whose vertices are the cells of the diagram, with edges between cells in the same row or column) is CDS-colorable, meaning that there exists a proper coloring of the vertices of the graph such that for all k > 0, the number of vertices with color < k equals the maximum size of the union of k independent sets of the graph.
References:
Quoted from FormalConjectures/Paper/LatinTableau.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 1 research or textbook statement: 1 open.
LatinTableau.SimpleGraph.LatinTableauConjecture
Open: stated without proof.
The Latin Tableau Conjecture: If G is the simple graph of a Young diagram, then G is CDS-colorable.
theorem LatinTableauConjecture (μ : YoungDiagram) :
μ.toSimpleGraph.CDSColorable
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/LatinTableau.lean, line 47.
Sources
TheoremLennon–Pittel conjecture on random stable matchings#
References: - On the Likely Number of Stable Marriages by Craig Lennon, PhD dissertation, The Ohio State University (2007). - On the Likely Number of Solutions for the Stable Marriage Problem by Craig Lennon and Boris Pittel, Combinatorics, Probability and Computing 18 (2009), 371–421.
Let \(S_n\) be the number of stable matchings under uniformly random complete strict preferences.
Quoted from FormalConjectures/Paper/LennonPittelStableMatchings.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 1 research or textbook statement: 1 open. It also has 1 test statement, counted here but not shown.
LennonPittel.lennon_pittel_conjecture
Open: stated without proof.
The Lennon–Pittel conjecture states that for every positive nonincreasing sequence \(\varepsilon_n \to 0\), the probability that the number \(S_n\) of stable matchings is at least \(\varepsilon_n \mathbb{E}[S_n]\) tends to one.
theorem lennon_pittel_conjecture
(ε : ℕ → ℝ) (hε_pos : ∀ n, 0 < ε n) (hε_antitone : Antitone ε)
(hε_tendsto : Tendsto ε atTop (𝓝 0)) :
Tendsto
(fun n ↦
(StableMarriage.uniformProfile n).toMeasure
{p | (StableMarriage.numStableMatchings p : ℝ) ≥
ε n * StableMarriage.expectedNumStableMatchings n})
atTop (𝓝 1)
Category research open; AMS 05 Combinatorics, 60 Probability theory and stochastic processes. Declared in FormalConjectures/Paper/LennonPittelStableMatchings.lean, line 53.
Sources
TheoremThe Manickam–Miklós–Singhi conjecture (1988)#
References: * [MM88] Manickam, N. and Miklós, D. (1988). "On the number of nonnegative partial sums of a nonnegative sum." Colloq. Math. Soc. János Bolyai 52, pp. 385--392. * [MS88] Manickam, N. and Singhi, N. M. (1988). "First distribution invariants and EKR theorems." J. Combin. Theory Ser. A 48, pp. 91--103. * [CSS14] Chowdhury, A., Sarkis, G. and Shahriari, S. (2014). "The Manickam–Miklós–Singhi conjectures for sets and vector spaces." J. Combin. Theory Ser. A 128, pp. 84--103. arXiv:1309.2212 * [Po15] Pokrovskiy, A. (2015). "A linear bound on the Manickam–Miklós–Singhi conjecture." J. Combin. Theory Ser. A 133, pp. 280--306. arXiv:1308.2176
Quoted from FormalConjectures/Paper/ManickamMiklosSinghiConjecture.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 3 research or textbook statements: 1 open and 2 solved. It also has 1 test statement, counted here but not shown.
ManickamMiklosSinghiConjecture.manickam_miklos_singhi_conjecture
Open: stated without proof.
The Manickam–Miklós–Singhi conjecture (1988).
If \(n \ge 4k\) and \(x_1, \dots, x_n\) are real numbers with \(x_1 + \dots + x_n = 0\), then at least \(\binom{n-1}{k-1}\) of the \(k\)-element subsets \(S \subseteq \{1, \dots, n\}\) have \(\sum_{i \in S} x_i \ge 0\). (The bound is attained by \(x = (n-1, -1, \dots, -1)\); the condition \(n \ge 4k\) cannot be weakened to \(n \ge 3k + 1\) in general.)
theorem manickam_miklos_singhi_conjecture :
∀ (n k : ℕ), 1 ≤ k → 4 * k ≤ n → ∀ x : Fin n → ℝ, ∑ i, x i = 0 →
(n - 1).choose (k - 1) ≤ nonnegSubsetCount n k x
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/ManickamMiklosSinghiConjecture.lean, line 56.
ManickamMiklosSinghiConjecture.manickam_miklos_singhi_conjecture.variants.pokrovskiy
Solved: stated here without proof.
Pokrovskiy (2015): the conjecture holds for \(n \ge C k\) with an absolute constant \(C\).
Pokrovskiy proved this with \(C = 10^{46}\), the first bound linear in \(k\).
Reference: [Po15].
theorem manickam_miklos_singhi_conjecture.variants.pokrovskiy :
∃ C : ℕ, ∀ (n k : ℕ), 1 ≤ k → C * k ≤ n → ∀ x : Fin n → ℝ, ∑ i, x i = 0 →
(n - 1).choose (k - 1) ≤ nonnegSubsetCount n k x
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/ManickamMiklosSinghiConjecture.lean, line 69.
ManickamMiklosSinghiConjecture.manickam_miklos_singhi_conjecture.variants.quadratic
Solved: stated here without proof.
Chowdhury–Sarkis–Shahriari (2014): the conjecture holds for \(n \ge 8k^2\).
Reference: [CSS14].
theorem manickam_miklos_singhi_conjecture.variants.quadratic (n k : ℕ) (hk : 1 ≤ k)
(hn : 8 * k ^ 2 ≤ n) (x : Fin n → ℝ) (hx : ∑ i, x i = 0) :
(n - 1).choose (k - 1) ≤ nonnegSubsetCount n k x
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/ManickamMiklosSinghiConjecture.lean, line 80.
Sources
TheoremMonochromatic quantum graphs (inherited vertex colorings)#
This file studies the existence of monochromatic quantum graphs: edge-coloured, edge-weighted complete graphs whose perfect matchings induce vertex colourings, with the property that
- every non-monochromatic inherited vertex colouring has total weight
0, while- each of the
Dmonochromatic colourings has total weight1.In the quantum-optics motivation, such a construction corresponds to generating high-dimensional multipartite GHZ-type states using probabilistic pair sources and linear optics (without additional resources), where interference patterns can be expressed as weighted sums over perfect matchings.
Main questions (informal)
- For
N = 4andD ≥ 4, does there exist such a graph/weighting?- For even
N ≥ 6andD ≥ 3, does there exist such a graph/weighting?Formalisation sketch
A quantum graph with
Nvertices andDcolours can be encoded by a weight functionW : EdgeN N D α → α(for a coefficient domainα).For each assignment of vertex indices
ι : V N → Fin D, we define a perfect-matching sumpmSumN N D W ι(a sum over perfect matchings, where each matching contributes the product of the corresponding edge weights determined byι). The equation systemEqSystemN N D Wrequires
pmSumN N D W ι = 1iffιis constant (all entries equal), and0otherwise.The open conjectures in this file ask for non-existence/existence of such
Wover various coefficient domains (e.g.ℂ,ℝ,ℤ, and restricted integer weights).References
[Krenn2017] M. Krenn, X. Gu, A. Zeilinger, "Quantum Experiments and Graphs: Multiparty States as Coherent Superpositions of Perfect Matchings", Physical Review Letters 119(24), 240403 (2017).
[MO2018] Vertex coloring inherited from perfect matchings (motivated by quantum physics), MathOverflow question 311325.
[Gu2019] X. Gu, M. Erhard, A. Zeilinger, M. Krenn, "Quantum experiments and graphs II: Quantum interference, computation, and state generation", PNAS 116(10), 4147–4155 (2019).
[Krenn2019] Questions on the Structure of Perfect Matchings inspired by Quantum Physics by M. Krenn, X. Gu, U. Soltész, Proc. 2nd Croatian Combinatorial Days, 57–70 (2019).
[Chandran2022] Edge-coloured graphs with only monochromatic perfect matchings and their connection to quantum physics by N. Chandran, S. Gajjala (2022).
[Chandran2024] Krenn–Gu conjecture for sparse graphs by N. Chandran, S. Gajjala, S. Illickan, M. Krenn, MFCS 2024.
[Ki26] A solver-free Lean 4 proof of the sharp bound \(D \le N - 2\) for monochromatic quantum graph equation systems over integral domains, commit
6c534038.[Ki26b] A solver-free Lean 4 proof that the monochromatic quantum graph equation system has no solution for \(N = 10\) and \(D = 8\) over integral domains, commit
a9309005.
Quoted from FormalConjectures/Paper/MonochromaticQuantumGraph.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 45 research or textbook statements: 16 open and 29 solved. It also has 3 test statements, counted here but not shown.
MonochromaticQuantumGraph.eqSystem4_no_solution_nnreal_ge4
Solved: stated here without proof.
Bogdanov: for \(N = 4\) and all \(D \geq 4\), no solution exists over \(\mathbb{R}_{\geq 0}\).
theorem eqSystem4_no_solution_nnreal_ge4 :
∀ D : Nat, D ≥ 4 →
¬ ∃ W : WeightsN 4 D ℝ≥0, EqSystemN 4 D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 346.
MonochromaticQuantumGraph.eqSystem_no_solution_nnreal_even_ge6_ge3
Solved: stated here without proof.
Bogdanov: for all even \(N \geq 6\) and \(D \geq 3\), no solution exists over \(\mathbb{R}_{\geq 0}\).
theorem eqSystem_no_solution_nnreal_even_ge6_ge3 :
∀ N D : Nat,
N ≥ 6 → Even N → D ≥ 3 →
¬ ∃ W : WeightsN N D ℝ≥0, EqSystemN N D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 353.
MonochromaticQuantumGraph.eqSystem_no_solution_even_ge4_d_eq_n_explicit
Solved: stated here; a Lean proof is at https://github.com/google-deepmind/formal-conjectures/blob/af88acbf9da0f26e3e934743a819e986e02f6875/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L1006.
For all even \(N \geq 4\) and \(D = N\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
The DeepMind prover agent has found a formal proof for this statement.
theorem eqSystem_no_solution_even_ge4_d_eq_n_explicit :
∀ N : Nat, N ≥ 4 → Even N →
¬ ∃ W : WeightsN N N ℂ, EqSystemN N N W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 383.
MonochromaticQuantumGraph.eqSystem4_no_solution_d4
Solved: stated here; a Lean proof is at https://github.com/google-deepmind/formal-conjectures/blob/af88acbf9da0f26e3e934743a819e986e02f6875/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L1021.
For \(N = 4\) and \(D = 4\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
This is the \(D = N\) case, proved using
eqSystem_no_solution_even_ge4_d_eq_n_explicit.
theorem eqSystem4_no_solution_d4 :
¬ ∃ W : WeightsN 4 4 ℂ, EqSystemN 4 4 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 395.
MonochromaticQuantumGraph.eqSystem4_no_solution_ge4
Solved: stated here; a Lean proof is at https://github.com/mo271/formal-conjectures/blob/4854c7233c58a7dce45fdd58b1826abf2c9c1a0f/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L549.
For \(N = 4\) and all \(D \geq 4\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
The DeepMind prover agent has found a formal proof of this statement.
theorem eqSystem4_no_solution_ge4 :
∀ D : Nat, D ≥ 4 →
¬ ∃ W : WeightsN 4 D ℂ, EqSystemN 4 D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 408.
MonochromaticQuantumGraph.eqSystem6_no_solution_d3
Solved: stated here; a Lean proof is at https://github.com/algal/krenn-gu-6x3-certificate/blob/c04696e515e0c02be140353fb52ea60c62e827b1/KrennGuCertificate/Unrestricted.lean#L201-L222.
For \(N = 6\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
A complete Lean 4 proof is available in the linked external certificate repository.
theorem eqSystem6_no_solution_d3 :
¬ ∃ W : WeightsN 6 3 ℂ, EqSystemN 6 3 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 422.
MonochromaticQuantumGraph.eqSystem6_no_solution_d4
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graph-n6-d4-lean/blob/7d30141a19714986d6f9e632314fd880c9a1e86e/lean/QuantumCR/FormalConjecturesWrapper.lean#L30-L37.
For \(N = 6\) and \(D = 4\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem6_no_solution_d4 :
¬ ∃ W : WeightsN 6 4 ℂ, EqSystemN 6 4 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 433.
MonochromaticQuantumGraph.eqSystem6_no_solution_d5
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graph-sharp-bound-lean/blob/6c5340384479dbb36129b2e0084449be2458cce2/lean/QuantumCR/FormalConjecturesWrappers.lean#L55-L62.
For \(N = 6\) and \(D = 5\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
The sharp bound \(D \le N - 2\) over an integral domain [Ki26] settles this: here \(D = N - 1\).
theorem eqSystem6_no_solution_d5 :
¬ ∃ W : WeightsN 6 5 ℂ, EqSystemN 6 5 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 445.
MonochromaticQuantumGraph.eqSystem6_no_solution_d6
Solved: stated here; a Lean proof is at https://github.com/google-deepmind/formal-conjectures/blob/af88acbf9da0f26e3e934743a819e986e02f6875/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L1074.
For \(N = 6\) and \(D = 6\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
This follows from
eqSystem_no_solution_even_ge4_d_eq_n_explicit.
theorem eqSystem6_no_solution_d6 :
¬ ∃ W : WeightsN 6 6 ℂ, EqSystemN 6 6 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 457.
MonochromaticQuantumGraph.eqSystem6_no_solution_ge3
Open: stated without proof.
For \(N = 6\) and all \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem6_no_solution_ge3 :
∀ D : Nat, D ≥ 3 →
¬ ∃ W : WeightsN 6 D ℂ, EqSystemN 6 D W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 464.
MonochromaticQuantumGraph.eqSystem8_no_solution_d3
Open: stated without proof.
For \(N = 8\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem8_no_solution_d3 :
¬ ∃ W : WeightsN 8 3 ℂ, EqSystemN 8 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 472.
MonochromaticQuantumGraph.eqSystem8_no_solution_d10
Solved: stated here; a Lean proof is at https://github.com/mo271/formal-conjectures/blob/2cc6df2e95835d759caedb15e36b70025b2eae2c/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L853.
For \(N = 8\) and \(D = 10\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
The DeepMind prover agent has found a formal proof of this statement.
theorem eqSystem8_no_solution_d10 :
¬ ∃ W : WeightsN 8 10 ℂ, EqSystemN 8 10 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 484.
MonochromaticQuantumGraph.eqSystem10_no_solution_d3
Open: stated without proof.
For \(N = 10\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem10_no_solution_d3 :
¬ ∃ W : WeightsN 10 3 ℂ, EqSystemN 10 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 491.
MonochromaticQuantumGraph.eqSystem10_no_solution_d4
Open: stated without proof.
For \(N = 10\) and \(D = 4\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem10_no_solution_d4 :
¬ ∃ W : WeightsN 10 4 ℂ, EqSystemN 10 4 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 498.
MonochromaticQuantumGraph.eqSystem10_no_solution_d5
Open: stated without proof.
For \(N = 10\) and \(D = 5\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem10_no_solution_d5 :
¬ ∃ W : WeightsN 10 5 ℂ, EqSystemN 10 5 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 505.
MonochromaticQuantumGraph.eqSystem10_no_solution_d6
Open: stated without proof.
For \(N = 10\) and \(D = 6\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem10_no_solution_d6 :
¬ ∃ W : WeightsN 10 6 ℂ, EqSystemN 10 6 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 512.
MonochromaticQuantumGraph.eqSystem10_no_solution_d7
Open: stated without proof.
For \(N = 10\) and \(D = 7\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem10_no_solution_d7 :
¬ ∃ W : WeightsN 10 7 ℂ, EqSystemN 10 7 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 519.
MonochromaticQuantumGraph.eqSystem10_no_solution_d8
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graph-n10-d8-lean/blob/a9309005c7a27a2615f8e7eebef7a1db017809ab/lean/QuantumGraphTenEightFC.lean#L5466-L5473.
For \(N = 10\) and \(D = 8\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
The sharp bound \(D \le N - 2\) of [Ki26] does not cover this equality case \(D = N - 2\); it is settled over an integral domain in [Ki26b].
theorem eqSystem10_no_solution_d8 :
¬ ∃ W : WeightsN 10 8 ℂ, EqSystemN 10 8 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 532.
MonochromaticQuantumGraph.eqSystem10_no_solution_d9
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graph-sharp-bound-lean/blob/6c5340384479dbb36129b2e0084449be2458cce2/lean/QuantumCR/FormalConjecturesWrappers.lean#L73-L80.
For \(N = 10\) and \(D = 9\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
The sharp bound \(D \le N - 2\) over an integral domain [Ki26] settles this: here \(D = N - 1\).
theorem eqSystem10_no_solution_d9 :
¬ ∃ W : WeightsN 10 9 ℂ, EqSystemN 10 9 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 543.
MonochromaticQuantumGraph.eqSystem10_no_solution_d10
Solved: stated here; a Lean proof is at https://github.com/google-deepmind/formal-conjectures/blob/af88acbf9da0f26e3e934743a819e986e02f6875/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L1167.
For \(N = 10\) and \(D = 10\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
This follows from the \(D = N\) case, see
eqSystem_no_solution_even_ge4_d_eq_n_explicit.
theorem eqSystem10_no_solution_d10 :
¬ ∃ W : WeightsN 10 10 ℂ, EqSystemN 10 10 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 554.
MonochromaticQuantumGraph.eqSystem12_no_solution_d3
Open: stated without proof.
For \(N = 12\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem12_no_solution_d3 :
¬ ∃ W : WeightsN 12 3 ℂ, EqSystemN 12 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 561.
MonochromaticQuantumGraph.eqSystem14_no_solution_d3
Open: stated without proof.
For \(N = 14\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem14_no_solution_d3 :
¬ ∃ W : WeightsN 14 3 ℂ, EqSystemN 14 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 568.
MonochromaticQuantumGraph.eqSystem16_no_solution_d3
Open: stated without proof.
For \(N = 16\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem16_no_solution_d3 :
¬ ∃ W : WeightsN 16 3 ℂ, EqSystemN 16 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 575.
MonochromaticQuantumGraph.eqSystem_no_solution_ge6_ge3
Open: stated without proof.
For all even \(N \geq 6\) and \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{C}\)?
theorem eqSystem_no_solution_ge6_ge3 :
∀ N D : Nat, N ≥ 6 → Even N → D ≥ 3 →
¬ ∃ W : WeightsN N D ℂ, EqSystemN N D W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 584.
MonochromaticQuantumGraph.eqSystem4_no_solution_ge4_real
Solved: stated here; a Lean proof is at https://github.com/mo271/formal-conjectures/blob/4854c7233c58a7dce45fdd58b1826abf2c9c1a0f/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L738.
For \(N = 4\) and all \(D \geq 4\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{R}\)?
This follows from the solution of the complex version of the problem (see
eqSystem4_no_solution_ge4)
theorem eqSystem4_no_solution_ge4_real :
∀ D : Nat, D ≥ 4 →
¬ ∃ W : WeightsN 4 D ℝ, EqSystemN 4 D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 601.
MonochromaticQuantumGraph.eqSystem6_no_solution_d3_real
Open: stated without proof.
For \(N = 6\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{R}\)?
theorem eqSystem6_no_solution_d3_real :
¬ ∃ W : WeightsN 6 3 ℝ, EqSystemN 6 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 609.
MonochromaticQuantumGraph.eqSystem6_no_solution_d5_real
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graph-sharp-bound-lean/blob/6c5340384479dbb36129b2e0084449be2458cce2/lean/QuantumCR/FormalConjecturesWrappers.lean#L64-L71.
For \(N = 6\) and \(D = 5\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{R}\)?
The sharp bound \(D \le N - 2\) over an integral domain [Ki26] settles this: here \(D = N - 1\).
theorem eqSystem6_no_solution_d5_real :
¬ ∃ W : WeightsN 6 5 ℝ, EqSystemN 6 5 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 620.
MonochromaticQuantumGraph.eqSystem6_no_solution_ge3_real
Open: stated without proof.
For \(N = 6\) and all \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{R}\)?
theorem eqSystem6_no_solution_ge3_real :
∀ D : Nat, D ≥ 3 →
¬ ∃ W : WeightsN 6 D ℝ, EqSystemN 6 D W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 627.
MonochromaticQuantumGraph.eqSystem8_no_solution_d3_real
Open: stated without proof.
For \(N = 8\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{R}\)?
theorem eqSystem8_no_solution_d3_real :
¬ ∃ W : WeightsN 8 3 ℝ, EqSystemN 8 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 635.
MonochromaticQuantumGraph.eqSystem10_no_solution_d3_real
Open: stated without proof.
For \(N = 10\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{R}\)?
theorem eqSystem10_no_solution_d3_real :
¬ ∃ W : WeightsN 10 3 ℝ, EqSystemN 10 3 W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 644.
MonochromaticQuantumGraph.eqSystem_no_solution_ge6_ge3_real
Open: stated without proof.
For all even \(N \geq 6\) and \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{R}\)?
theorem eqSystem_no_solution_ge6_ge3_real :
∀ N D : Nat, N ≥ 6 → Even N → D ≥ 3 →
¬ ∃ W : WeightsN N D ℝ, EqSystemN N D W
Category research open; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 651.
MonochromaticQuantumGraph.eqSystem4_no_solution_ge4_int
Solved: stated here; a Lean proof is at https://github.com/mo271/formal-conjectures/blob/4854c7233c58a7dce45fdd58b1826abf2c9c1a0f/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L836.
For \(N = 4\) and all \(D \geq 4\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\)?
This follows from the solution of the complex version of the problem (see
eqSystem4_no_solution_ge4).
theorem eqSystem4_no_solution_ge4_int :
∀ D : Nat, D ≥ 4 →
¬ ∃ W : WeightsN 4 D ℤ, EqSystemN 4 D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 667.
MonochromaticQuantumGraph.eqSystem6_no_solution_d3_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L32-L39.
For \(N = 6\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\)?
theorem eqSystem6_no_solution_d3_int :
¬ ∃ W : WeightsN 6 3 ℤ, EqSystemN 6 3 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 678.
MonochromaticQuantumGraph.eqSystem6_no_solution_d5_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L41-L48.
For \(N = 6\) and \(D = 5\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\)?
theorem eqSystem6_no_solution_d5_int :
¬ ∃ W : WeightsN 6 5 ℤ, EqSystemN 6 5 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 688.
MonochromaticQuantumGraph.eqSystem6_no_solution_ge3_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L50-L58.
For \(N = 6\) and all \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\)?
theorem eqSystem6_no_solution_ge3_int :
∀ D : Nat, D ≥ 3 →
¬ ∃ W : WeightsN 6 D ℤ, EqSystemN 6 D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 698.
MonochromaticQuantumGraph.eqSystem8_no_solution_d3_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L60-L67.
For \(N = 8\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\)?
theorem eqSystem8_no_solution_d3_int :
¬ ∃ W : WeightsN 8 3 ℤ, EqSystemN 8 3 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 709.
MonochromaticQuantumGraph.eqSystem10_no_solution_d3_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L69-L76.
For \(N = 10\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\)?
theorem eqSystem10_no_solution_d3_int :
¬ ∃ W : WeightsN 10 3 ℤ, EqSystemN 10 3 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 720.
MonochromaticQuantumGraph.eqSystem_no_solution_ge6_ge3_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L78-L86.
For all even \(N \geq 6\) and \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\)?
theorem eqSystem_no_solution_ge6_ge3_int :
∀ N D : Nat, N ≥ 6 → Even N → D ≥ 3 →
¬ ∃ W : WeightsN N D ℤ, EqSystemN N D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 730.
MonochromaticQuantumGraph.eqSystem4_no_solution_ge4_trinary_int
Solved: stated here; a Lean proof is at https://github.com/mo271/formal-conjectures/blob/4854c7233c58a7dce45fdd58b1826abf2c9c1a0f/FormalConjectures/Paper/MonochromaticQuantumGraph.lean#L936.
For \(N = 4\) and all \(D \geq 4\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\) with weights in \(\{-1, 0, 1\}\)?
This follows from the complex version, see
eqSystem4_no_solution_ge4.
theorem eqSystem4_no_solution_ge4_trinary_int :
∀ D : Nat, D ≥ 4 →
¬ ∃ W : WeightsN 4 D ℤ,
(∀ e, W e = (-1 : ℤ) ∨ W e = 0 ∨ W e = 1) ∧
EqSystemN 4 D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 746.
MonochromaticQuantumGraph.eqSystem6_no_solution_d3_trinary_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L88-L97.
For \(N = 6\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\) with weights in \(\{-1, 0, 1\}\)?
theorem eqSystem6_no_solution_d3_trinary_int :
¬ ∃ W : WeightsN 6 3 ℤ,
(∀ e, W e = (-1 : ℤ) ∨ W e = 0 ∨ W e = 1) ∧
EqSystemN 6 3 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 759.
MonochromaticQuantumGraph.eqSystem6_no_solution_d5_trinary_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L99-L108.
For \(N = 6\) and \(D = 5\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\) with weights in \(\{-1, 0, 1\}\)?
theorem eqSystem6_no_solution_d5_trinary_int :
¬ ∃ W : WeightsN 6 5 ℤ,
(∀ e, W e = (-1 : ℤ) ∨ W e = 0 ∨ W e = 1) ∧
EqSystemN 6 5 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 771.
MonochromaticQuantumGraph.eqSystem6_no_solution_ge3_trinary_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L110-L120.
For \(N = 6\) and all \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\) with weights in \(\{-1, 0, 1\}\)?
theorem eqSystem6_no_solution_ge3_trinary_int :
∀ D : Nat, D ≥ 3 →
¬ ∃ W : WeightsN 6 D ℤ,
(∀ e, W e = (-1 : ℤ) ∨ W e = 0 ∨ W e = 1) ∧
EqSystemN 6 D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 783.
MonochromaticQuantumGraph.eqSystem8_no_solution_d3_trinary_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L122-L131.
For \(N = 8\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\) with weights in \(\{-1, 0, 1\}\)?
theorem eqSystem8_no_solution_d3_trinary_int :
¬ ∃ W : WeightsN 8 3 ℤ,
(∀ e, W e = (-1 : ℤ) ∨ W e = 0 ∨ W e = 1) ∧
EqSystemN 8 3 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 796.
MonochromaticQuantumGraph.eqSystem10_no_solution_d3_trinary_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L133-L142.
For \(N = 10\) and \(D = 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\) with weights in \(\{-1, 0, 1\}\)?
theorem eqSystem10_no_solution_d3_trinary_int :
¬ ∃ W : WeightsN 10 3 ℤ,
(∀ e, W e = (-1 : ℤ) ∨ W e = 0 ∨ W e = 1) ∧
EqSystemN 10 3 W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 809.
MonochromaticQuantumGraph.eqSystem_no_solution_ge6_ge3_trinary_int
Solved: stated here; a Lean proof is at https://github.com/KitaKen1/monochromatic-quantum-graphs-lean/blob/d3ed1892ef181f5f5f5d61d9b5817f05b53a6675/lean/QuantumLean/FormalConjecturesWrappers.lean#L144-L154.
For all even \(N \geq 6\) and \(D \geq 3\), does there exist no solution to the monochromatic quantum graph equation system over \(\mathbb{Z}\) with weights in \(\{-1, 0, 1\}\)?
theorem eqSystem_no_solution_ge6_ge3_trinary_int :
∀ N D : Nat, N ≥ 6 → Even N → D ≥ 3 →
¬ ∃ W : WeightsN N D ℤ,
(∀ e, W e = (-1 : ℤ) ∨ W e = 0 ∨ W e = 1) ∧
EqSystemN N D W
Category research solved; AMS 05 Combinatorics, 14 Algebraic geometry, 81 Quantum theory. Declared in FormalConjectures/Paper/MonochromaticQuantumGraph.lean, line 821.
Sources
TheoremEnergy-critical NLS in three dimensions.#
This file states an a priori estimate for the energy-critical nonlinear Schrödinger equation on \(ℝ^3\). By 'soft' arguments, this bound implies global well-posedness in the energy space, scattering, asymptotic completeness, and uniform regularity (all of which are less elementary to state). This is remarked on p. 770 and p. 793 in the referenced article which first proved the a priori bound.
The main theorem is: -
NLS_apriori: a bound on the space-time \(L^10\) norm in terms of the initial energy for local smooth solutions to the NLS equation.References
- Colliander, Keel, Staffilani, Takaoka, Tao, Annals of Mathematics 167 (2008) proves the a priori estimate, and thereby, global well-posedness.
Quoted from FormalConjectures/Paper/NLSCritical.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 1 research or textbook statement: 1 solved.
NLSCritical.NLS_apriori
Solved: stated here without proof.
The \(L^10_{t,x}\) a priori estimate for local schwartz solutions.
theorem NLS_apriori :
∃ f : ℝ → ℝ, ∀ l > 0, ∀ s : LocalSchwartzSolution l,
L10_local l s.u ≤ f (energy (s.u 0))
Category research solved; AMS 35 Partial differential equations. Declared in FormalConjectures/Paper/NLSCritical.lean, line 74.
Sources
TheoremThe 1-2-3 conjecture (Karoński–Łuczak–Thomason 2004; proved by Keusch 2024)#
References: * [KLT04] Karoński, M., Łuczak, T. and Thomason, A. (2004). "Edge weights and vertex colours." J. Combin. Theory Ser. B 91, pp. 151--157. * [ABDMRT07] Addario-Berry, L., Dalal, K., McDiarmid, C., Reed, B. A. and Thomason, A. (2007). "Vertex-colouring edge-weightings." Combinatorica 27, pp. 1--12. * [KKP10] Kalkowski, M., Karoński, M. and Pfender, F. (2010). "Vertex-coloring edge-weightings: towards the 1-2-3-conjecture." J. Combin. Theory Ser. B 100, pp. 347--349. * [Ke24] Keusch, R. (2024). "A solution to the 1-2-3 conjecture." J. Combin. Theory Ser. B 166, pp. 183--202. arXiv:2303.02611
Quoted from FormalConjectures/Paper/OneTwoThreeConjecture.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 5 research or textbook statements: 5 solved.
OneTwoThreeConjecture.one_two_three_conjecture
Solved: stated here without proof.
The 1-2-3 conjecture (Karoński–Łuczak–Thomason 2004), proved by Keusch (2024).
Every finite simple graph with no isolated edge admits an edge weighting with weights in \(\{1, 2, 3\}\) such that adjacent vertices have different weighted degrees.
theorem one_two_three_conjecture :
∀ {V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V) [DecidableRel G.Adj],
NoIsolatedEdge G →
∃ w : Sym2 V → ℕ, (∀ e ∈ G.edgeFinset, 1 ≤ w e ∧ w e ≤ 3) ∧
IsVertexColouringWeighting G w
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/OneTwoThreeConjecture.lean, line 66.
OneTwoThreeConjecture.one_two_three_conjecture.variants.one_to_five
Solved: stated here without proof.
Kalkowski–Karoński–Pfender (2010): weights in \(\{1, \dots, 5\}\) suffice.
Reference: [KKP10].
theorem one_two_three_conjecture.variants.one_to_five
{V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V) [DecidableRel G.Adj]
(hG : NoIsolatedEdge G) :
∃ w : Sym2 V → ℕ, (∀ e ∈ G.edgeFinset, 1 ≤ w e ∧ w e ≤ 5) ∧
IsVertexColouringWeighting G w
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/OneTwoThreeConjecture.lean, line 79.
OneTwoThreeConjecture.one_two_three_conjecture.variants.one_to_thirty
Solved: stated here without proof.
Addario-Berry–Dalal–McDiarmid–Reed–Thomason (2007): weights in \(\{1, \dots, 30\}\) suffice.
Reference: [ABDMRT07]; see also the introduction of [KKP10].
theorem one_two_three_conjecture.variants.one_to_thirty
{V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V) [DecidableRel G.Adj]
(hG : NoIsolatedEdge G) :
∃ w : Sym2 V → ℕ, (∀ e ∈ G.edgeFinset, 1 ≤ w e ∧ w e ≤ 30) ∧
IsVertexColouringWeighting G w
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/OneTwoThreeConjecture.lean, line 92.
OneTwoThreeConjecture.one_two_three_conjecture.variants.isolated_edge_necessary
Proved here.
The hypothesis "no isolated edge" is necessary.
A single edge
K₂has no vertex-colouring edge weighting at all: both endpoints receive the weight of the unique edge as their weighted degree.
theorem one_two_three_conjecture.variants.isolated_edge_necessary :
¬ ∃ w : Sym2 (Fin 2) → ℕ, IsVertexColouringWeighting (completeGraph (Fin 2)) w
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/OneTwoThreeConjecture.lean, line 106.
OneTwoThreeConjecture.one_two_three_conjecture.variants.two_weights_insufficient
Proved here.
Weights \(\{1, 2\}\) do not suffice: the triangle.
In
K₃the three vertex sums area + b,a + c,b + cfor the three edge weightsa, b, c, and they are pairwise distinct only ifa, b, care, which is impossible with two available weights. Hence the constant3in the conjecture cannot be lowered to2.
theorem one_two_three_conjecture.variants.two_weights_insufficient :
¬ ∃ w : Sym2 (Fin 3) → ℕ, (∀ e ∈ (completeGraph (Fin 3)).edgeFinset, 1 ≤ w e ∧ w e ≤ 2) ∧
IsVertexColouringWeighting (completeGraph (Fin 3)) w
Category research solved; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/OneTwoThreeConjecture.lean, line 132.
Sources
TheoremParities of partition numbers#
There are several conjectures on parities of partition numbers. The most famous conjecture is the Parkin-Shanks conjecture, which states that the natural density of
nwhere the partition numberp(n)is even (resp. odd) exists and equals1/2.There are several related (weaker) results toward the conjecture. Kolberg showed that
p(n)takes each parity infinitely often. Subbarao conjectured that every arithmetic progressionr (mod t)contains infinitely manynwithp(n)even and infinitely manynwithp(n)odd; the even case was proved by Ono and the odd case by Radu. Quantitative lower bounds for the number ofn ≤ Xwithp(n)even (resp. odd) have also been studied. The best known bounds are≫ √X log log Xfor even values (Bellaïche–Nicolas) and≫ √Xfor odd values (Zheng, in an appendix to Ono–Swaminathan). Ono–Swaminathan also proved that both parities occur infinitely often along the quadratic progressions(D m² + 1) / 24, and Ono conjectured the same for every nonconstant integer-valued polynomial that is eventually positive.References: * On the distribution of parity in the partition function, T. R. Parkin, D. Shanks, Math. Comp. 21 (1967), 466–480. * Note on the parity of the partition function, O. Kolberg, Math. Scand. 7 (1959), 377–378. * Some remarks on the partition function, M. V. Subbarao, Amer. Math. Monthly 73 (1966), 851–854. * Parity of the partition function in arithmetic progressions, K. Ono, J. Reine Angew. Math. 472 (1996), 1–16. * Distribution of parity of the partition function in arithmetic progressions, S. Ahlgren, Indag. Math. (N.S.) 10 (1999), 173–181. * Parity of the partition function, K. Ono, Adv. Math. 225 (2010), 349–366. * A proof of Subbarao's conjecture, C.-S. Radu, J. Reine Angew. Math. 672 (2012), 161–175. * Parité des coefficients de formes modulaires, J. Bellaïche, J.-L. Nicolas, Ramanujan J. 40 (2016), 1–44. * Nonzero coefficients of half-integral weight modular forms mod ℓ, J. Bellaïche, B. Green, K. Soundararajan, Res. Math. Sci. 5 (2018), Paper No. 6. * Parity of the partition function in quadratic progressions (with an appendix by Q.-Y. Zheng), K. Ono, A. Swaminathan, arXiv:2509.09553. * [Cox] D. A. Cox, Primes of the Form \(x^2 + ny^2\), 2nd ed., Wiley, 2013.
Quoted from FormalConjectures/Paper/PartitionParity.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 16 research or textbook statements: 2 open, 13 solved and 1 textbook result.
PartitionParity.kolberg
Solved: stated here without proof.
p(n)is even for infinitely manynand odd for infinitely manyn. (Kolberg)
theorem kolberg :
{n : ℕ | Even (partitionNumber n)}.Infinite ∧ {n : ℕ | Odd (partitionNumber n)}.Infinite
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 68.
PartitionParity.parkin_shanks
Open: stated without proof.
The natural density of
nwhere the partition numberp(n)is even (resp. odd) exists and equals1/2.
theorem parkin_shanks :
{n : ℕ | Even (partitionNumber n)}.HasDensity (1 / 2) ∧
{n : ℕ | Odd (partitionNumber n)}.HasDensity (1 / 2)
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 75.
PartitionParity.subbarao.even
Solved: stated here without proof.
Every arithmetic progression contains infinitely many
nwherep(n)is even. Conjectured by Subbarao and proved by Ono.
theorem subbarao.even : ∀ r t, 0 < t →
{n : ℕ | n ≡ r [MOD t] ∧ Even (partitionNumber n)}.Infinite
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 83.
PartitionParity.subbarao.odd
Solved: stated here without proof.
Every arithmetic progression contains infinitely many
nwherep(n)is odd. Conjectured by Subbarao; Ono proved it for every progression containing at least onenwithp(n)odd, and Radu showed that every progression contains such ann.
theorem subbarao.odd : ∀ r t, 0 < t →
{n : ℕ | n ≡ r [MOD t] ∧ Odd (partitionNumber n)}.Infinite
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 91.
PartitionParity.ahlgren.even
Solved: stated here without proof.
For every arithmetic progression
r (mod t), the number ofn ≤ Xwithn ≡ r (mod t)andp(n)even is≫ √X. (Ahlgren)
theorem ahlgren.even : ∀ r t, 0 < t →
(fun X : ℝ ↦ √X) =O[atTop]
fun X : ℝ ↦ ({n : ℕ | n ≤ X ∧ n ≡ r [MOD t] ∧ Even (partitionNumber n)}.ncard : ℝ)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 98.
PartitionParity.ahlgren.odd
Solved: stated here without proof.
For every arithmetic progression
r (mod t), the number ofn ≤ Xwithn ≡ r (mod t)andp(n)odd is≫ √X / log X. Ahlgren proved this for every progression containing at least onenwithp(n)odd; by Radu's theorem every progression does.
theorem ahlgren.odd : ∀ r t, 0 < t →
(fun X : ℝ ↦ √X / X.log) =O[atTop]
fun X : ℝ ↦ ({n : ℕ | n ≤ X ∧ n ≡ r [MOD t] ∧ Odd (partitionNumber n)}.ncard : ℝ)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 107.
PartitionParity.bellaiche_nicolas.even
Solved: stated here without proof.
The number of
n ≤ Xwithp(n)even is≫ √X log log X. (Bellaïche–Nicolas)
theorem bellaiche_nicolas.even :
(fun X : ℝ ↦ √X * X.log.log) =O[atTop]
fun X : ℝ ↦ ({n : ℕ | n ≤ X ∧ Even (partitionNumber n)}.ncard : ℝ)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 114.
PartitionParity.bellaiche_nicolas.even_explicit
Solved: stated here without proof.
The number of
n ≤ xwithp(n)even is at least0.069 √x log log xfor everyx > 1. (Bellaïche–Nicolas)
theorem bellaiche_nicolas.even_explicit : ∀ x : ℝ, 1 < x →
0.069 * √x * x.log.log ≤ ({n : ℕ | n ≤ x ∧ Even (partitionNumber n)}.ncard : ℝ)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 122.
PartitionParity.bellaiche_nicolas.odd_explicit
Solved: stated here without proof.
The number of
n ≤ xwithp(n)odd is at least0.037 √x / (log x)^(7/8)for everyx ≥ 2. (Bellaïche–Nicolas)
theorem bellaiche_nicolas.odd_explicit : ∀ x : ℝ, 2 ≤ x →
0.037 * √x / (x.log) ^ (7 / 8 : ℝ) ≤ ({n : ℕ | n ≤ x ∧ Odd (partitionNumber n)}.ncard : ℝ)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 129.
PartitionParity.bellaiche_green_soundararajan.odd
Solved: stated here without proof.
The number of
n ≤ Xwithp(n)odd is≫ √X / log log X. (Bellaïche–Green–Soundararajan)
theorem bellaiche_green_soundararajan.odd :
(fun X : ℝ ↦ √X / X.log.log) =O[atTop]
fun X : ℝ ↦ ({n : ℕ | n ≤ X ∧ Odd (partitionNumber n)}.ncard : ℝ)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 136.
PartitionParity.ono_swaminathan.quadratic
Solved: stated here without proof.
For square-free
D > 1withD ≡ 23 (mod 24), both parities occur infinitely often amongp((D m² + 1) / 24)asmranges over the positive integers coprime to6. Note that24 ∣ D m² + 1for suchm. Conjectured by Ono and proved by Ono–Swaminathan.
theorem ono_swaminathan.quadratic : ∀ D : ℕ, 1 < D → Squarefree D → D % 24 = 23 →
{m : ℕ | m.Coprime 6 ∧ Even (partitionNumber ((D * m ^ 2 + 1) / 24))}.Infinite ∧
{m : ℕ | m.Coprime 6 ∧ Odd (partitionNumber ((D * m ^ 2 + 1) / 24))}.Infinite
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 145.
PartitionParity.ono_swaminathan.odd_bound
Solved: stated here without proof.
The odd half of Theorem 1 of Ono–Swaminathan, with its effective bound: for square-free
D > 1withD ≡ 23 (mod 24)there is anmcoprime to6withm ≤ 12 h(-D) + 2such thatp((D m² + 1) / 24)is odd, whereh(-D)is the class number ofℚ(√-D). Hereℚ(√-D)isAdjoinRoot (X ^ 2 + D), a number field sinceX ^ 2 + Dis irreducible overℚforD > 0.
theorem ono_swaminathan.odd_bound (D : ℕ) (hD : 1 < D) (hsq : Squarefree D) (h23 : D % 24 = 23) :
haveI : Fact (Irreducible (X ^ 2 + C (D : ℚ))) :=
⟨irreducible_X_sq_add_C_of_pos (Nat.cast_pos.2 (by lia))⟩
∃ m : ℕ, m.Coprime 6 ∧
m ≤ 12 * NumberField.classNumber (AdjoinRoot (X ^ 2 + C (D : ℚ))) + 2 ∧
Odd (partitionNumber ((D * m ^ 2 + 1) / 24))
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 155.
PartitionParity.classNumber_eq_ncard_reducedForms
Textbook result, stated without proof.
For square-free
D ≡ 3 (mod 4), the discriminant-Dis fundamental and the class number ofℚ(√-D)equals the number of reduced primitive positive-definite binary quadratic forms of discriminant-D[Cox, Theorem 2.8]. This identification is used in Zheng's appendix to Ono–Swaminathan.
theorem classNumber_eq_ncard_reducedForms (D : ℕ) (hsq : Squarefree D) (h3 : D % 4 = 3) :
haveI : Fact (Irreducible (X ^ 2 + C (D : ℚ))) :=
⟨irreducible_X_sq_add_C_of_pos (Nat.cast_pos.2 (by lia))⟩
NumberField.classNumber (AdjoinRoot (X ^ 2 + C (D : ℚ))) =
{⟨a, b, c⟩ : ℤ × ℤ × ℤ | IsReducedForm D a b c}.ncard
Category textbook; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 174.
PartitionParity.zheng.liminf
Solved: stated here; a Lean proof assuming ono_swaminathan.odd_bound, classNumber_eq_ncard_reducedForms is at https://github.com/AxiomMath/PartitionZheng/blob/9bfb4326c4ea1e00016a842d7cc145e5c4e0684a/Solution/Basic.lean#L17.
Zheng's explicit lower bound:
liminf_{X → ∞} N_odd(X) / √X ≥ 243 / (64 √6 π⁵), whereN_odd(X)is the number ofn ≤ Xwithp(n)odd [Ono-Swaminathan, Appendix A, Corollary 2].
theorem zheng.liminf :
((243 / (64 * √6 * π ^ 5) : ℝ) : EReal) ≤
liminf (fun X : ℝ ↦
((({n : ℕ | n ≤ X ∧ Odd (partitionNumber n)}.ncard : ℝ) / √X : ℝ) : EReal)) atTop
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 188.
PartitionParity.zheng.odd
Solved: stated here without proof.
The number of
n ≤ Xwithp(n)odd is≫ √X.
theorem zheng.odd :
(fun X : ℝ ↦ √X) =O[atTop]
fun X : ℝ ↦ ({n : ℕ | n ≤ X ∧ Odd (partitionNumber n)}.ncard : ℝ)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 196.
PartitionParity.ono.polynomial
Open: stated without proof.
Ono's conjecture, as stated in Section 1 of Ono–Swaminathan: if
gis a nonconstant integer-valued polynomial that is eventually positive, thenp(g(n))is even for infinitely manynand odd for infinitely manyn.
theorem ono.polynomial (g : ℚ[X]) (hg : 0 < g.natDegree)
(hint : ∀ n : ℕ, ∃ k : ℤ, g.eval (n : ℚ) = k)
(hpos : ∀ᶠ n : ℕ in atTop, 0 < g.eval (n : ℚ)) :
{n : ℕ | Even (partitionNumber ⌊g.eval (n : ℚ)⌋₊)}.Infinite ∧
{n : ℕ | Odd (partitionNumber ⌊g.eval (n : ℚ)⌋₊)}.Infinite
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/PartitionParity.lean, line 205.
Sources
TheoremPfister's problem on the Pythagoras number of \(\mathbb{R}(X_1, \dots, X_n)\)#
The Pythagoras number \(p(K)\) of a field \(K\) is the least \(p\) such that every sum of squares in \(K\) is a sum of \(p\) squares, i.e. the least element of
pythagorasBounds K.Artin's solution of Hilbert's 17th problem shows that a positive semidefinite rational function in \(\mathbb{R}(X_1, \dots, X_n)\) is a sum of squares, and Pfister showed that \(2^n\) squares suffice ([Pfister1967, Theorem 1]; for the field, Corollary 1 of Theorem 2 in [Pfister1971]). Since sums of squares are positive semidefinite, \(p(\mathbb{R}(X_1, \dots, X_n)) \le 2^n\) [Pfister1995, p. 95].
Problem 1 of [Pfister1971, §4] asks for the true value of \(p(\mathbb{R}(X_1, \dots, X_n))\). The question is often posed as: is \(p(\mathbb{R}(X_1, \dots, X_n)) = 2^n\), i.e. is Pfister's bound optimal? See e.g. [Benoist2017, Question 0.2].
Problem 1 itself quotes the lower bound \(n + 1 \le p(\mathbb{R}(X_1, \dots, X_n))\) from Cassels' theorem [Cassels1964]. For \(n \ge 2\) the best known bounds are \(n + 2 \le p(\mathbb{R}(X_1, \dots, X_n)) \le 2^n\) [Pfister1995, p. 97], where the lower bound follows from the Cassels–Ellison–Pfister theorem [CEP1971]. The bounds agree for \(n = 2\), so the value is known for \(n \le 2\) and open for every \(n \ge 3\). The survey [MerkurjevParimala2025, §5.2] records the question as open even for \(\mathbb{R}(X_1, X_2, X_3)\) (Question 5.7).
References: - [Pfister1971] A. Pfister, Sums of squares in real function fields, pp. 297–300 in Actes du Congrès International des Mathématiciens, Tome 1 (Nice, 1970), Gauthier-Villars, 1971, IMU scan. - [Pfister1967] A. Pfister, Zur Darstellung definiter Funktionen als Summe von Quadraten, Invent. Math. 4 (1967), 229–237, doi:10.1007/BF01425382. - [Cassels1964] J. W. S. Cassels, On the representation of rational functions as sums of squares, Acta Arith. 9 (1964), 79–82, doi:10.4064/aa-9-1-79-82. - [Pfister1995] A. Pfister, Quadratic forms with applications to algebraic geometry and topology, London Math. Soc. Lecture Note Ser. 217, Cambridge University Press, 1995. - [CEP1971] J. W. S. Cassels, W. J. Ellison, A. Pfister, On sums of squares and on elliptic curves over function fields, J. Number Theory 3 (1971), 125–149, doi:10.1016/0022-314X(71)90030-8. - [Benoist2017] O. Benoist, On Hilbert's 17th problem in low degree, Algebra Number Theory 11 (2017), 929–959, doi:10.2140/ant.2017.11.929, arXiv:1602.07330. - [MerkurjevParimala2025] A. Merkurjev, R. Parimala, Quadratic forms beyond arithmetic, Notices Amer. Math. Soc. 72 (2025), no. 7, 711–718, doi:10.1090/noti3192.
Quoted from FormalConjectures/Paper/PfisterPythagorasNumber.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 9 research or textbook statements: 2 open, 5 solved and 2 textbook results. It also has 1 test statement, counted here but not shown.
PfisterPythagorasNumber.pfister_problem
Open: stated without proof.
Pfister's problem (Problem 1 of [Pfister1971, §4]): what is the true value of \(p(\mathbb{R}(X_1, \dots, X_n))\), as a function of \(n\)? It is \(1\), \(2\), \(4\) for \(n = 0, 1, 2\) (
pfister_problem.variants.zero,pfister_problem.variants.one,pfister_problem.variants.two) and open for every \(n \ge 3\), where only the bounds \(n + 2 \le p(\mathbb{R}(X_1, \dots, X_n)) \le 2^n\) are known.
theorem pfister_problem :
∀ n, IsLeast (pythagorasBounds (MvRatFunc (Fin n) ℝ)) (pfister_problem.answer n)
Category research open; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 90.
PfisterPythagorasNumber.pfister_problem.variants.eq_two_pow
Open: stated without proof.
Pfister's problem in its common yes/no form (e.g. Question 0.2 of [Benoist2017]): is \(p(\mathbb{R}(X_1, \dots, X_n)) = 2^n\) for every \(n\), i.e. is Pfister's bound optimal? This holds for \(n \le 2\) and is open for every \(n \ge 3\).
theorem pfister_problem.variants.eq_two_pow :
∀ n : ℕ, IsLeast (pythagorasBounds (MvRatFunc (Fin n) ℝ)) (2 ^ n)
Category research open; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 100.
PfisterPythagorasNumber.pfister_problem.variants.upper_bound
Solved: stated here; a Lean proof is at https://github.com/anatoliiohorodnyk/lean-fc-proofs/blob/a25a41b3e51f6987edeafcc1602e80e6d30e6f05/Proofs/T_PfisterPythagorasNumber_pfister_problem_variants_upper_bound.lean#L1006.
Pfister's theorem: every sum of squares in \(\mathbb{R}(X_1, \dots, X_n)\) is a sum of \(2^n\) squares [Pfister1995, p. 95]; this is Corollary 1 of Theorem 2 in [Pfister1971]. For positive semidefinite polynomials it is [Pfister1967, Theorem 1], the quantitative refinement of Artin's theorem
Hilbert17.hilbert_17th_probleminFormalConjectures/HilbertProblems/17.lean.
theorem pfister_problem.variants.upper_bound (n : ℕ) :
2 ^ n ∈ pythagorasBounds (MvRatFunc (Fin n) ℝ)
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 112.
PfisterPythagorasNumber.pfister_problem.variants.cassels
Solved: stated here; a Lean proof is at https://github.com/anatoliiohorodnyk/lean-fc-proofs/blob/a25a41b3e51f6987edeafcc1602e80e6d30e6f05/Proofs/T_PfisterPythagorasNumber_pfister_problem_variants_cassels.lean#L434.
Cassels' theorem [Cassels1964], as quoted in Problem 1 of [Pfister1971, §4]: \(1 + X_1^2 + \dots + X_n^2\) is not a sum of \(n\) squares in \(\mathbb{R}(X_1, \dots, X_n)\).
theorem pfister_problem.variants.cassels (n : ℕ) :
¬IsSumSqOfLength n (algebraMap (MvPolynomial (Fin n) ℝ) (MvRatFunc (Fin n) ℝ)
(1 + ∑ i, MvPolynomial.X i * MvPolynomial.X i))
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 122.
PfisterPythagorasNumber.pfister_problem.variants.add_one_le
Proved here.
The lower bound \(n + 1 \le p(\mathbb{R}(X_1, \dots, X_n))\) quoted in Problem 1 of [Pfister1971, §4]: \(1 + X_1^2 + \dots + X_n^2\) is a sum of \(n + 1\) squares but, by Cassels' theorem
pfister_problem.variants.cassels, not of \(n\) squares. It is superseded bypfister_problem.variants.lower_boundfor \(n \ge 2\).
theorem pfister_problem.variants.add_one_le (n : ℕ) {p : ℕ}
(hp : p ∈ pythagorasBounds (MvRatFunc (Fin n) ℝ)) : n + 1 ≤ p
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 134.
PfisterPythagorasNumber.pfister_problem.variants.lower_bound
Solved: stated here without proof.
The lower bound \(n + 2 \le p(\mathbb{R}(X_1, \dots, X_n))\) for \(n \ge 2\) [Pfister1995, p. 97], a consequence of the Cassels–Ellison–Pfister theorem [CEP1971]. The hypothesis \(n \ge 2\) is needed: \(p(\mathbb{R}(X)) = 2 < 3\).
theorem pfister_problem.variants.lower_bound (n : ℕ) (hn : 2 ≤ n) {p : ℕ}
(hp : p ∈ pythagorasBounds (MvRatFunc (Fin n) ℝ)) : n + 2 ≤ p
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 149.
PfisterPythagorasNumber.pfister_problem.variants.zero
Textbook result, proved here.
\(p(\mathbb{R}(X_1, \dots, X_n)) = 1\) for \(n = 0\), i.e. \(p(\mathbb{R}) = 1\): here the bounds \(n + 1\) and \(2^n\) of
pfister_problem.variants.add_one_leandpfister_problem.variants.upper_boundagree. CompareisLeast_pythagorasBounds_real, the same value forℝitself.
theorem pfister_problem.variants.zero : IsLeast (pythagorasBounds (MvRatFunc (Fin 0) ℝ)) 1
Category textbook; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 159.
PfisterPythagorasNumber.pfister_problem.variants.one
Textbook result, proved here.
\(p(\mathbb{R}(X)) = 2\) [Pfister1995, p. 96]: Pfister's bound gives \(p \le 2\), and Cassels' theorem
pfister_problem.variants.casselsgives \(p \ge 2\) throughpfister_problem.variants.add_one_le, since \(1 + X^2\) is a sum of two squares that is not a square in \(\mathbb{R}(X)\).
theorem pfister_problem.variants.one : IsLeast (pythagorasBounds (MvRatFunc (Fin 1) ℝ)) 2
Category textbook; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 170.
PfisterPythagorasNumber.pfister_problem.variants.two
Proved here.
\(p(\mathbb{R}(X_1, X_2)) = 4\) [CEP1971], as recorded in [Pfister1971, §4] and [Pfister1995, p. 96]: the bounds \(n + 2\) and \(2^n\) agree when \(n = 2\).
theorem pfister_problem.variants.two : IsLeast (pythagorasBounds (MvRatFunc (Fin 2) ℝ)) 4
Category research solved; AMS 11 Number theory, 12 Field theory and polynomials, 14 Algebraic geometry. Declared in FormalConjectures/Paper/PfisterPythagorasNumber.lean, line 179.
Sources
TheoremPrime Tuples Conjecture#
Reference: [FLC07] Friedlander, J. B. and Luca, F. and Stoiciu, M., On the irrationality of a divisor function series. Integers (2007).
Quoted from FormalConjectures/Paper/PrimeTuples.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 1 research or textbook statement: 1 open.
PrimeTuplesConjecture.prime_tuples_conjecture
Open: stated without proof.
For any
k ≥ 2, leta₁,...,aₖandb₁,...,bₖbe integers withaᵢ > 0. Suppose that for every primepthere exists an integernsuch thatp ∤ ∏ i, (aᵢ n + bᵢ). Then there exist infinitely manynsuch thataᵢ n + bᵢis prime for alli.
theorem prime_tuples_conjecture {k : ℕ} (hk : 2 ≤ k) (a : Fin k → ℕ+) (b : Fin k → ℕ)
(hab : ∀ p, p.Prime → ∃ n, ¬ p ∣ ∏ i, (a i * n + b i)) :
Set.Infinite {n | ∀ i : Fin k, (a i * n + b i).Prime}
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/PrimeTuples.lean, line 37.
Sources
TheoremPudlák's conjectures on incompleteness in the finite domain#
References: * [CR79] Cook, S. A. and Reckhow, R. A. (1979). "The relative efficiency of propositional proof systems." J. Symbolic Logic 44, pp. 36--50. * [HH88] Hartmanis, J. and Hemachandra, L. A. (1988). "Complexity classes without machines: on complete languages for UP." Theoret. Comput. Sci. 58, pp. 129--142. * [KP89] Krajíček, J. and Pudlák, P. (1989). "Propositional proof systems, the consistency of first order theories and the complexity of computations." J. Symbolic Logic 54, pp. 1063--1079. * [MP91] Megiddo, N. and Papadimitriou, C. H. (1991). "On total functions, existence theorems and computational complexity." Theoret. Comput. Sci. 81, pp. 317--324. * [Pa94] Papadimitriou, C. H. (1994). "On the complexity of the parity argument and other inefficient proofs of existence." J. Comput. System Sci. 48, pp. 498--532. * [KMT03] Köbler, J., Messner, J., and Torán, J. (2003). "Optimal proof systems imply complete sets for promise classes." Inform. and Comput. 184, pp. 71--92. * [Pu17] Pudlák, P. (2017). "Incompleteness in the finite domain." Bull. Symbolic Logic 23, pp. 405--441. arXiv:1601.01487 * [Kh22] Khaniki, E. (2022). "New relations and separations of conjectures about incompleteness in the finite domain." J. Symbolic Logic 87, pp. 912--937. arXiv:1904.01362
Quoted from FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 7 research or textbook statements: 4 open, 2 solved and 1 textbook result. It also has 4 API statements, counted here but not shown.
PudlakFiniteDomain.sat_no_p_optimal_proof_system
Open: stated without proof.
SAT has no p-optimal proof system (Pudlák's conjecture
SAT[Pu17]).No proof system for
SATp-simulates every other proof system forSAT. Since the existence of a p-optimal proof system depends only on the polynomial-time many-one degree of the language [KMT03], the conjecture is stated here for an arbitrary NP-complete language. Equivalently [Pu17], for every consistent polynomial-time axiomatized theoryT ⊇ S¹₂there is a proof system forSATwhose soundnessTcannot prove.
theorem sat_no_p_optimal_proof_system (L : DecisionProblem) (hL : IsCompleteFor NP L) :
¬∃ P : List Bool → List Bool, IsPOptimalProofSystem L P
Category research open; AMS 03 Mathematical logic and foundations, 68 Computer science. Declared in FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean, line 137.
PudlakFiniteDomain.tfnp_no_complete_problem
Open: stated without proof.
TFNP has no complete problem (Megiddo–Papadimitriou [MP91]; Pudlák's conjecture
TFNP[Pu17]).No total NP search problem is complete under polynomial-time many-one reductions of search problems. Equivalently [Pu17], for every consistent polynomial-time axiomatized theory
T ⊇ S¹₂some total NP search problem is not polynomially reducible to any total NP search problem provably total inT.
theorem tfnp_no_complete_problem : ¬∃ T : TFNPProblem, T.IsComplete
Category research open; AMS 03 Mathematical logic and foundations, 68 Computer science. Declared in FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean, line 151.
PudlakFiniteDomain.up_no_complete_language
Open: stated without proof.
UP has no complete language (Hartmanis–Hemachandra [HH88]; Pudlák's conjecture
UP[Pu17]).No language accepted by an unambiguous polynomial-time verifier is complete for
UPunder polynomial-time many-one reductions.
theorem up_no_complete_language : ¬∃ L : DecisionProblem, IsCompleteFor UP L
Category research open; AMS 03 Mathematical logic and foundations, 68 Computer science. Declared in FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean, line 162.
PudlakFiniteDomain.np_inter_conp_no_complete_language
Open: stated without proof.
NP ∩ coNP has no complete language (Pudlák's conjecture
NP ∩ coNP[Pu17]).No language in
NP ∩ coNPis complete for that class under polynomial-time many-one reductions.
theorem np_inter_conp_no_complete_language :
¬∃ L : DecisionProblem, IsCompleteFor (NP ∩ coNP) L
Category research open; AMS 03 Mathematical logic and foundations, 68 Computer science. Declared in FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean, line 172.
PudlakFiniteDomain.tfnp_no_complete_problem.variants.exists_of_NP_eq_coNP
Solved: stated here without proof.
If
NP = coNPthen TFNP has a complete problem [MP91, Pu17].Under
NP = coNPthe search problem "given a CNF, find a satisfying assignment or a short proof of unsatisfiability" is total and complete.
theorem tfnp_no_complete_problem.variants.exists_of_NP_eq_coNP (h : NP = coNP) :
∃ T : TFNPProblem, T.IsComplete
Category research solved; AMS 03 Mathematical logic and foundations, 68 Computer science. Declared in FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean, line 183.
PudlakFiniteDomain.tfnp_no_complete_problem.variants.NP_ne_coNP
Proved here.
The conjecture implies
NP ≠ coNP[Pu17].
theorem tfnp_no_complete_problem.variants.NP_ne_coNP
(h : ¬∃ T : TFNPProblem, T.IsComplete) : NP ≠ coNP
Category research solved; AMS 03 Mathematical logic and foundations, 68 Computer science. Declared in FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean, line 191.
PudlakFiniteDomain.sat_no_p_optimal_proof_system.variants.exists_of_P_eq_NP
Textbook result, stated without proof.
If
P = NPthen every NP-complete language has a p-optimal proof system.The map sending
πto itself whenπ ∈ Land to a fixed element ofLotherwise is then polynomial-time, and every proof systemQforLis p-simulated by it viaQitself.
theorem sat_no_p_optimal_proof_system.variants.exists_of_P_eq_NP (h : P = NP)
(L : DecisionProblem) (hL : IsCompleteFor NP L) (hne : ∃ y, L y = true) :
∃ P : List Bool → List Bool, IsPOptimalProofSystem L P
Category textbook; AMS 03 Mathematical logic and foundations, 68 Computer science. Declared in FormalConjectures/Paper/PudlakFiniteDomainConjectures.lean, line 202.
Sources
TheoremReed's omega, delta, and chi conjecture#
References: - B. Reed, ω Δ and χ, J. Graph Theory 27 (1998) 177-212. - openproblemgarden - mathoverflow/37923 asked by user Andrew D. King
Quoted from FormalConjectures/Paper/ReedOmegaDeltaChi.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 3 research or textbook statements: 3 open.
ReedOmegaDeltaChi.reed_omega_delta_chi_conjecture
Open: stated without proof.
For a graph \(G\), we define \(\Delta(G)\) to be the maximum degree, \(\omega(G)\) to be the size of the largest clique subgraph, and \(\chi(G)\) to be the chromatic number. Reed's omega, delta, and chi conjecture states that
\[\chi(G) \leq \lceil \frac{1}{2}(\omega(G) + \Delta(G) + 1) \rceil.\]
theorem reed_omega_delta_chi_conjecture :
∀ {V : Type} (G : SimpleGraph V),
let χ := G.chromaticNumber
let ω := G.ecliqueNum
let Δ := G.emaxDegree
2 * χ ≤ ω + Δ + 2
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/ReedOmegaDeltaChi.lean, line 41.
ReedOmegaDeltaChi.reed_omega_delta_chi_conjecture_for_finite_graphs
Open: stated without proof.
For a finite graph \(G\), we define \(\Delta(G)\) to be the maximum degree, \(\omega(G)\) to be the size of the largest clique subgraph, and \(\chi(G)\) to be the chromatic number. Reed's omega, delta, and chi conjecture states that
\[\chi(G) \leq \lceil \frac{1}{2}(\omega(G) + \Delta(G) + 1) \rceil.\]
theorem reed_omega_delta_chi_conjecture_for_finite_graphs :
∀ {V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V) [DecidableRel G.Adj],
let χ := G.chromaticNumber
let ω := G.cliqueNum
let Δ := G.maxDegree
2 * χ ≤ ω + Δ + 2
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/ReedOmegaDeltaChi.lean, line 55.
ReedOmegaDeltaChi.reed_conjecture_Δ_6_ω_2
Open: stated without proof.
The simplest open case is when \(\Delta(G) = 6\) and \(\omega(G) = 2\).
theorem reed_conjecture_Δ_6_ω_2 :
∀ {V : Type} (G : SimpleGraph V), G.emaxDegree = 6 ∧ G.cliqueNum = 2 → G.chromaticNumber ≤ 5
Category research open; AMS 05 Combinatorics. Declared in FormalConjectures/Paper/ReedOmegaDeltaChi.lean, line 67.
Sources
TheoremEquivalents to the Riemann Hypothesis#
This file contains formal statements that are known to be equivalent to the Riemann Hypothesis, following the survey [Co26], §4. The statement of the Riemann Hypothesis itself is in
FormalConjectures.Millennium.RiemannHypothesis.References: * [Co26] A. Connes, The Riemann Hypothesis: Past, Present and a Letter Through Time, 2026.
Quoted from FormalConjectures/Paper/RiemannHypothesisEquivalents.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 10 research or textbook statements: 5 open and 5 solved. It also has 2 API statements, counted here but not shown.
RiemannHypothesis.robin_criterion
Solved: stated here without proof.
Robin's Criterion. The Riemann Hypothesis is equivalent to
\[ \sigma(n) < e ^ {\gamma} n\log\log n \]for all \(n > 5040\), where \(\gamma\) is the Euler-Mascheroni constant and \(\sigma(n)\) is the sum of divisors.
theorem robin_criterion :
RiemannHypothesis ↔ ∀ n > 5040, σ 1 n < (exp eulerMascheroniConstant) * n * log (log n)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 46.
RiemannHypothesis.robin_criterion_rhs
Open: stated without proof.
The statement that Robin's criterion holds.
theorem robin_criterion_rhs {n : ℕ} (hn : n > 5040) :
σ 1 n < exp eulerMascheroniConstant * n * log (log n)
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 52.
RiemannHypothesis.lagarias_criterion
Solved: stated here without proof.
Lagarias' Criterion. A refinement of Robin's criterion: the Riemann Hypothesis is equivalent to
\[ \sigma(n) < H_n + e^{H_n}\log H_n \]for all \(n \geq 2\), where \(H_n = 1 + 1/2 + \cdots + 1/n\) is the \(n\)th harmonic number.
Note that [Co26] states this for all \(n \geq 1\), but at \(n = 1\) both sides equal \(1\); Lagarias' original formulation is the non-strict inequality for all \(n \geq 1\), with equality only at \(n = 1\).
theorem lagarias_criterion : RiemannHypothesis ↔
∀ n > 1, σ 1 n < harmonic n + exp (harmonic n) * log (harmonic n)
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 67.
RiemannHypothesis.lagarias_criterion_rhs
Open: stated without proof.
The statement that Lagarias' criterion holds.
theorem lagarias_criterion_rhs {n : ℕ} (hn : 1 < n) :
σ 1 n < harmonic n + exp (harmonic n) * log (harmonic n)
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 73.
RiemannHypothesis.li_criterion
Solved: stated here without proof.
Li's Criterion. The Riemann Hypothesis is equivalent to the positivity of
\[ \lambda_n := \sum_{\rho}\left(1 - \left(1 - \frac{1}{\rho}\right)^n\right) \]for each \(n > 0\).
theorem li_criterion : RiemannHypothesis ↔ ∀ n > 0, 0 < lambda n
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 102.
RiemannHypothesis.li_criterion_rhs
Open: stated without proof.
The statement that Li's criterion holds.
theorem li_criterion_rhs {n : ℕ} (hn : 0 < n) : 0 < lambda n
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 107.
RiemannHypothesis.beurling_nyman_criterion
Solved: stated here without proof.
Beurling-Nyman Criterion. The Riemann Hypothesis is equivalent to the statement that the set of finite linear combination \(\sum_{\nu = 1}^n c_{\nu}\rho_{\theta_{\nu}}\) is dense in \(L^2(0, 1)\), when ranging over \(0 < \theta_{\nu}\leq 1\) and \(\sum_{\nu = 1}^n c_{\nu}\theta_{\nu} = 0\).
theorem beurling_nyman_criterion : RiemannHypothesis ↔
Dense { fractScalarInvSumL2 n c θ | (n) (c) (θ)
(hθ : ∀ ν, θ ν ∈ Set.Ioc 0 1) (h : ∑ ν, c ν * θ ν = 0) }
Category research solved; AMS 11 Number theory, 28 Measure and integration. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 136.
RiemannHypothesis.beurling_nyman_criterion_rhs
Open: stated without proof.
The statement that the Beurling-Nyman criterion holds.
theorem beurling_nyman_criterion_rhs :
Dense { fractScalarInvSumL2 n c θ | (n) (c) (θ)
(hθ : ∀ ν, θ ν ∈ Set.Ioc 0 1) (h : ∑ ν, c ν * θ ν = 0) }
Category research open; AMS 11 Number theory, 28 Measure and integration. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 143.
RiemannHypothesis.weil_positivity_criterion
Solved: stated here without proof.
Weil's Positivity Criterion. The Riemann Hypothesis is equivalent to the non-positivity of Weil factor sums on the convolution of test functions. In [Co26] this is expressed as
\[ \sum_v W_v(g\star g^*) \leq 0 \]for all compactly-supported smooth functions \(g : \mathbb{R}_+^{\times} \to \mathbb{C}\) such that the Mellin transform of \(g\) vanishes at \(\pm i / 2\), where \(g^*(x) := \bar{g}(x^{-1})\) and \(W_v\) are the multiplicative Weil factors defined in [Co26]. We formalise this as the corresponding additive statement (via \(x = e^u\)), since convolution in mathlib is additive, and restrict to real-valued test functions \(g\), which suffices for the equivalence.
theorem weil_positivity_criterion :
RiemannHypothesis ↔ ∀ g : C_c(ℝ, ℝ), ContDiff ℝ ∞ g → IsTestFunction g →
weilArchimedean (g ⋆ fun x ↦ g (-x)) +
∑' p : Nat.Primes, weilNonArchimedean p (g ⋆ fun x ↦ g (-x)) ≤ 0
Category research solved; AMS 11 Number theory, 46 Functional analysis. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 173.
RiemannHypothesis.weil_positivity_criterion_rhs
Open: stated without proof.
The statement that the Weil criterion holds.
theorem weil_positivity_criterion_rhs {g : C_c(ℝ, ℝ)} (hg : ContDiff ℝ ∞ g)
(h : IsTestFunction g) :
weilArchimedean (g ⋆ fun x ↦ g (-x)) +
∑' p : Nat.Primes, weilNonArchimedean p (g ⋆ fun x ↦ g (-x)) ≤ 0
Category research open; AMS 11 Number theory, 46 Functional analysis. Declared in FormalConjectures/Paper/RiemannHypothesisEquivalents.lean, line 181.
Sources
TheoremMoments of the Riemann zeta function on the critical line#
The moments \(\frac{1}{T}\int_0^T |\zeta(1/2 + it)|^{2k}\,dt\) are conjectured to be asymptotic to \(c_k (\log T)^{k^2}\) for some constants \(c_k\). This is a theorem for \(k = 1\) (Hardy–Littlewood, \(c_1 = 1\)) and \(k = 2\) (Ingham, \(c_2 = 1/(2\pi^2)\)), and these are the only proven cases. Conrey–Ghosh and Conrey–Gonek conjectured \(c_3 = 42 a_3 / 9!\) and \(c_4 = 24024 a_4 / 16!\), with \(a_k\) the arithmetic factor \(a_k = \prod_p (1 - 1/p)^{k^2} \sum_{m \ge 0} \binom{m+k-1}{m}^2 p^{-m}\); Keating–Snaith conjectured \(c_k = a_k f_k\) with \(f_k = \prod_{j=0}^{k-1} j!/(j+k)!\) from random matrix theory, recovering \(g_k = (k^2)!\,f_k = 1, 2, 42, 24024\).
The statements and constants below are taken from §3.4.5 of [Co26].
References: - [Co26] A. Connes, The Riemann Hypothesis: Past, Present and a Letter Through Time, arXiv:2602.04022, §3.4.5. - [In26] A. E. Ingham, Mean-value theorems in the theory of the Riemann zeta-function, Proc. London Math. Soc. 27 (1926), 273–300. - [CG98] J. B. Conrey, A. Ghosh, A conjecture for the sixth power moment of the Riemann zeta-function, Internat. Math. Res. Notices 1998, no. 15, 775–780. - [CGo01] J. B. Conrey, S. Gonek, High moments of the Riemann zeta-function, Duke Math. J. 107 (2001), no. 3, 577–604. - [KS00] J. P. Keating, N. C. Snaith, Random matrix theory and \(\zeta(1/2+it)\), Commun. Math. Phys. 214 (2000), no. 1, 57–89.
Quoted from FormalConjectures/Paper/RiemannZetaMoments.lean in Formal Conjectures (Google DeepMind) at commit 2055e5ad, Apache-2.0, as are the docstrings and Lean statements below.
The file states 6 research or textbook statements: 4 open and 2 solved. It also has 1 test statement, counted here but not shown.
RiemannZetaMoments.moment_isEquiv
Open: stated without proof.
The asymptotic behaviour of the \(k\)th moment of the Riemann zeta function is conjectured to be
\[ \frac{1}{T}\int_0^T |\zeta(1/2 + it)|^{2k}dt \sim c_k \log(T)^{k^2}, \]for some constant \(c_k\).
theorem moment_isEquiv (k : ℕ) : ∃ c > (0 : ℝ),
moment k ~[atTop] fun T ↦ c * T.log ^ (k ^ 2)
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannZetaMoments.lean, line 70.
RiemannZetaMoments.moment_isEquiv₁
Solved: stated here without proof.
The asymptotic behaviour of the first moment of the Riemann zeta function was proved by Hardy and Littlewood, where \(c_1 = 1\) [Co26, §3.4.5].
theorem moment_isEquiv₁ : moment 1 ~[atTop] fun T ↦ T.log
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannZetaMoments.lean, line 77.
RiemannZetaMoments.moment_isEquiv₂
Solved: stated here without proof.
The asymptotic behaviour of the second moment of the Riemann zeta function was proved by Ingham [In26], where \(c_2 = 1/(2\pi^2)\).
theorem moment_isEquiv₂ : moment 2 ~[atTop] fun T ↦ (1 / (2 * π ^ 2)) * T.log ^ 4
Category research solved; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannZetaMoments.lean, line 83.
RiemannZetaMoments.moment_isEquiv₃
Open: stated without proof.
The constant in the asymptotic formula for the 3rd zeta moment is conjectured to be \(42a_3/9!\) [CG98].
theorem moment_isEquiv₃ : moment 3 ~[atTop] fun T ↦ 42 * arithmeticFactor 3 / 9 ! * T.log ^ 9
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannZetaMoments.lean, line 109.
RiemannZetaMoments.moment_isEquiv₄
Open: stated without proof.
The constant in the asymptotic formula for the 4th zeta moment is conjectured to be \(24024a_4/16!\) [CGo01].
theorem moment_isEquiv₄ :
moment 4 ~[atTop] fun T ↦ 24024 * arithmeticFactor 4 / 16 ! * T.log ^ 16
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannZetaMoments.lean, line 115.
RiemannZetaMoments.moment_isEquivₖ
Open: stated without proof.
The Keating–Snaith conjecture [KS00] for the \(k\)th moment of the Riemann zeta function, provides the value of \(c_k\) in the asymptotic formula [Co26, §3.4.5].
theorem moment_isEquivₖ (k : ℕ) : moment k ~[atTop]
fun T ↦ (arithmeticFactor k * ∏ j ∈ Finset.range k, (j ! : ℝ) / (j + k) !) *
T.log ^ (k ^ 2)
Category research open; AMS 11 Number theory. Declared in FormalConjectures/Paper/RiemannZetaMoments.lean, line 122.
Sources
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