Foundations of adic spaces, part IV — étale sites, families and dagger geometry
The declarations the status of Tau Ceti's roadmap names as Tau Ceti has them at commit ace60277.
TheoremUnits of the Monsky–Washnitzer algebra#
Over a complete ultrametric normed field, an
overconvergent series is a unit of W iff its constant coefficient is nonzero and strictly
dominates the norm of every other coefficient.
TauCeti.Dagger.isUnit_washnitzerAlgebra_iff.{u_1, u_2} {σ : Type u_1} {K : Type u_2} [NormedField K]
[IsUltrametricDist K] [CompleteSpace K] (f : ↥(TauCeti.Dagger.washnitzerAlgebra σ K)) :
IsUnit f ↔
MvPowerSeries.constantCoeff ↑f ≠ 0 ∧
∀ (t : σ →₀ ℕ), t ≠ 0 → ‖(MvPowerSeries.coeff t) ↑f‖ < ‖MvPowerSeries.constantCoeff ↑f‖
Uses 3 · Used by 1
TheoremTauCeti.Dagger.washnitzerAlgebra.isUnit_toTate_iff#
An overconvergent series is a unit of the Tate algebra iff it is a unit of the Monsky–Washnitzer algebra: the inverse of an overconvergent series is overconvergent.
TauCeti.Dagger.washnitzerAlgebra.isUnit_toTate_iff.{u_1, u_2} {σ : Type u_1} {K : Type u_2}
[NormedField K] [IsUltrametricDist K] [CompleteSpace K]
(f : ↥(TauCeti.Dagger.washnitzerAlgebra σ K)) :
IsUnit ((TauCeti.Dagger.washnitzerAlgebra.toTate σ K) f) ↔ IsUnit f
Lean
Formalized in Tau Ceti as TauCeti.Dagger.washnitzerAlgebra.isUnit_toTate_iff.
Sources
Uses 3
TheoremPrimitives of overconvergent series are overconvergent#
Over an ultrametric normed field
of characteristic zero, the termwise primitive with respect to Xᵢ of an overconvergent series is
overconvergent. See MvPowerSeries.IsRestricted.primitive for the radius-by-radius version.
TauCeti.Dagger.primitive_mem_washnitzerAlgebra.{u_1, u_2} {σ : Type u_1} {K : Type u_2}
[NormedField K] [IsUltrametricDist K] [CharZero K] {f : MvPowerSeries σ K}
(hf : f ∈ TauCeti.Dagger.washnitzerAlgebra σ K) (i : σ) :
(MvPowerSeries.primitive i) f ∈ TauCeti.Dagger.washnitzerAlgebra σ K
Uses 1
TheoremThe Gauss norm bound for primitives#
Over a normed field of characteristic zero, for
polyradii 0 ≤ c' ≤ c with c'ᵢ < cᵢ, there is C ≥ 0 such that for every f with a Gauss norm
at c, ∫ f dXᵢ has a Gauss norm at c' and gaussNorm c' (∫ f dXᵢ) ≤ C * gaussNorm c f.
MvPowerSeries.exists_gaussNorm_primitive_le.{u_1, u_2} {σ : Type u_1} {K : Type u_2} [NormedField K]
[CharZero K] (c c' : σ → ℝ) (i : σ) (hc' : ∀ (j : σ), 0 ≤ c' j) (hle : ∀ (j : σ), c' j ≤ c j)
(hlt : c' i < c i) :
∃ C,
0 ≤ C ∧
∀ (f : MvPowerSeries σ K),
MvPowerSeries.HasGaussNorm norm c f →
MvPowerSeries.HasGaussNorm norm c' ((MvPowerSeries.primitive i) f) ∧
MvPowerSeries.gaussNorm norm c' ((MvPowerSeries.primitive i) f) ≤
C * MvPowerSeries.gaussNorm norm c f
TheoremDistinguishing automorphisms of Monsky–Washnitzer algebras#
Over a complete
nonarchimedean field K, every nonzero overconvergent series f in the variables Option σ,
for finite σ, is carried by a triangular automorphism Y ↦ Y, Xᵢ ↦ Xᵢ + Y ^ α i of
K⟨X, Y⟩† to a series which, as a restricted series in the variable Y = none over the Tate
algebra in the variables σ, is distinguished of some degree s at radius 1 with a unit
coefficient in degree s.
TauCeti.Dagger.washnitzerAlgebra.exists_triangularEquiv_isDistinguished_isUnit.{u_1, u_3}
{σ : Type u_1} {K : Type u_3} [NormedField K] [IsUltrametricDist K] [CompleteSpace K] [Finite σ]
(f : ↥(TauCeti.Dagger.washnitzerAlgebra (Option σ) K)) (hf : f ≠ 0) :
∃ α,
∃ (hα : ∀ (i : σ), α i ≠ 0),
∃ s,
TauCeti.PowerSeries.IsDistinguished 1 s
↑(MvPowerSeries.restrictedOptionEquiv
((TauCeti.Dagger.washnitzerAlgebra.toTate (Option σ) K)
((TauCeti.Dagger.washnitzerAlgebra.triangularEquiv α hα) f))) ∧
IsUnit
((PowerSeries.coeff s)
↑(MvPowerSeries.restrictedOptionEquiv
((TauCeti.Dagger.washnitzerAlgebra.toTate (Option σ) K)
((TauCeti.Dagger.washnitzerAlgebra.triangularEquiv α hα) f))))
Lean
Formalized in Tau Ceti as TauCeti.Dagger.washnitzerAlgebra.exists_triangularEquiv_isDistinguished_isUnit.
Sources
- Tau Ceti documentation:
TauCeti.Dagger.washnitzerAlgebra.exists_triangularEquiv_isDistinguished_isUnit - Source of
TauCeti.Dagger.washnitzerAlgebra.exists_triangularEquiv_isDistinguished_isUnitin TauCeti/RingTheory/Dagger/Distinguished.lean - Tau Ceti roadmap status: Foundations of adic spaces, part IV — étale sites, families and dagger geometry
TheoremRadius selection for distinguished overconvergent series#
Let g be an overconvergent
series in the variables Option σ which, as a series in Y = X none over the Tate algebra in the
variables σ, is distinguished of degree s at radius 1 with a unit coefficient g_s. Then for
every ρ₀ > 1 there are radii 1 < ρ ≤ r ≤ ρ₀ such that g is restricted at r, and its
coefficient slices gₘ, which are restricted at ρ, form a series G = ∑ₘ gₘ Yᵐ over the
series restricted at ρ that is distinguished of degree s at radius r, with g_s a unit.
This is the radius selection behind Weierstrass division by g inside the Monsky–Washnitzer
algebra. A single common radius ρ = r > 1 does not suffice in general.
TauCeti.Dagger.exists_isDistinguished_isUnit_of_isDistinguished_one.{u_1, u_3} {σ : Type u_1}
{K : Type u_3} [NormedField K] [IsUltrametricDist K] [CompleteSpace K]
{g : ↥(TauCeti.Dagger.washnitzerAlgebra (Option σ) K)} {s : ℕ}
(hg :
TauCeti.PowerSeries.IsDistinguished 1 s
↑(MvPowerSeries.restrictedOptionEquiv
((TauCeti.Dagger.washnitzerAlgebra.toTate (Option σ) K) g)))
(hu :
IsUnit
((PowerSeries.coeff s)
↑(MvPowerSeries.restrictedOptionEquiv
((TauCeti.Dagger.washnitzerAlgebra.toTate (Option σ) K) g))))
{ρ₀ : ℝ} (hρ₀ : 1 < ρ₀) :
∃ ρ,
∃ (x : Fact (0 < ρ)),
∃ r,
1 < ρ ∧
ρ ≤ r ∧
r ≤ ρ₀ ∧
MvPowerSeries.IsRestricted (fun x => r) ↑g ∧
∃ G,
(∀ (m : ℕ),
↑((PowerSeries.coeff m) G) =
(PowerSeries.coeff m) ((MvPowerSeries.optionEquivLeft σ K) ↑g)) ∧
TauCeti.PowerSeries.IsDistinguished r s G ∧ IsUnit ((PowerSeries.coeff s) G)
Lean
Formalized in Tau Ceti as TauCeti.Dagger.exists_isDistinguished_isUnit_of_isDistinguished_one.
Sources
- Tau Ceti documentation:
TauCeti.Dagger.exists_isDistinguished_isUnit_of_isDistinguished_one - Source of
TauCeti.Dagger.exists_isDistinguished_isUnit_of_isDistinguished_onein TauCeti/RingTheory/Dagger/Distinguished.lean - Tau Ceti roadmap status: Foundations of adic spaces, part IV — étale sites, families and dagger geometry
DefinitionTauCeti.Dagger.washnitzerAlgebra#
The Monsky–Washnitzer algebra R⟨X⟩† of overconvergent power series: the series
restricted at some constant radius ρ > 1.
TauCeti.Dagger.washnitzerAlgebra.{u_1, u_2} (σ : Type u_1) (R : Type u_2) [NormedCommRing R]
[IsUltrametricDist R] : Subalgebra R (MvPowerSeries σ R)
Used by 8
DefinitionTauCeti.Dagger.washnitzerAlgebra.toTate#
The inclusion of the Monsky–Washnitzer algebra into the unit-radius Tate algebra R{X/1},
through which W carries the Gauss norm.
TauCeti.Dagger.washnitzerAlgebra.toTate.{u_1, u_2} (σ : Type u_1) (R : Type u_2) [NormedCommRing R]
[IsUltrametricDist R] :
↥(TauCeti.Dagger.washnitzerAlgebra σ R) →ₐ[R] ↥(MvPowerSeries.IsRestricted.subring fun x => 1)
Uses 1 · Used by 6
DefinitionIsomorphisms of Monsky–Washnitzer algebras from inverse substitutions#
If two families of
unit-ball polynomials without constant term are inverse to each other under substitution, the
substitutions are mutually inverse R-algebra isomorphisms R⟨X⟩† ≃ R⟨Y⟩†.
TauCeti.Dagger.washnitzerAlgebra.substEquiv.{u_1, u_2, u_3} {σ : Type u_1} {τ : Type u_2}
{R : Type u_3} [NormedCommRing R] [IsUltrametricDist R] [NormOneClass R] [Finite σ]
(a : σ → MvPolynomial τ R) (ha₀ : ∀ (s : σ), MvPolynomial.constantCoeff (a s) = 0)
(ha₁ : ∀ (s : σ) (t : τ →₀ ℕ), ‖(a s).coeff t‖ ≤ 1) [Finite τ] (b : τ → MvPolynomial σ R)
(hb₀ : ∀ (t : τ), MvPolynomial.constantCoeff (b t) = 0)
(hb₁ : ∀ (t : τ) (u : σ →₀ ℕ), ‖(b t).coeff u‖ ≤ 1)
(hab : ∀ (s : σ), (MvPolynomial.aeval b) (a s) = MvPolynomial.X s)
(hba : ∀ (t : τ), (MvPolynomial.aeval a) (b t) = MvPolynomial.X t) :
↥(TauCeti.Dagger.washnitzerAlgebra σ R) ≃ₐ[R] ↥(TauCeti.Dagger.washnitzerAlgebra τ R)
Uses 2 · Used by 1
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