JBlaschkeDerivBound to DeltaRange

TheoremJBlaschkeDerivBound#

Let \(B>1\) and \(0 < r' < r < R<1\). If \(f:\mathbb{C}\to\mathbb{C}\) is a function analytic on neighborhoods of points in \(\overline{\mathbb{D}_1}\) with \(f(0)=1\) and \(|f(z)|\leq B\) for all \(|z|\leq R\), then for all \(|z|\leq r'\)

\[ |L_f'(z)|\leq\frac{16\log(B)\,r^2}{(r-r')^3}. \]
Proof

By Lemma DiskBound we immediately know that \(|B_f(z)|\leq B\) for all \(|z|\leq R\). Now since \(L_f=J_{B_f}\) by Definition JBlaschke, by Theorem LogOfAnalyticFunction we know that

\[ L_f(0)=0\qquad\text{and}\qquad \Re L_f(z)=\log|B_f(z)|-\log|B_f(0)|\leq\log|B_f(z)|\leq\log B \]

for all \(|z|\leq r\). Note that in the above

\[ 0=\log|f(0)|\leq\log|B_f(0)| \]

because of Lemma norm-fOfZero-le-norm-BlaschkeOfZero. So by Theorem BorelCaratheodoryDeriv, it follows that

\[ |L_f'(z)|\leq\frac{16\log(B)\,r^2}{(r-r')^3} \]

for all \(|z|\leq r'\).

Lean

Formalized as JBlaschkeDerivBound.

Sources
Uses 9 · Used by 1

TheoremFinalBound#

Let \(B>1\) and \(0 < r' < r < R' < R<1\). If \(f:\mathbb{C}\to\mathbb{C}\) is a function analytic on neighborhoods of points in \(\overline{\mathbb{D}_1}\) with \(f(0)=1\) and \(|f(z)|\leq B\) for all \(|z|\leq R\), then for all \(z\in\overline{\mathbb{D}_{r'}}\setminus\mathcal{K}_f(R')\) we have

\[ \left|\frac{f'}{f}(z)-\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-\rho}\right| \leq\left(\frac{16r^2}{(r-r')^3}+\frac{1}{(R^2/R'-R')\,\log(R/R')}\right)\log B. \]
Proof

Since \(z\in\overline{\mathbb{D}_{r'}}\setminus\mathcal{K}_f(R')\) we know that \(z\not\in\mathcal{K}_f(R')\); thus, by Definition CFunction we know that

\[ C_f(z)=\frac{f(z)}{\displaystyle\prod_{\rho\in\mathcal{K}_f(r)}(z-\rho)^{m_f(\rho)}}. \]

Substituting this into Definition BlaschkeB we have that

\[ B_f(z)=f(z)\prod_{\rho\in\mathcal{K}_f(r)} \left(\frac{R-z\overline{\rho}/R}{z-\rho}\right)^{m_f(\rho)}. \]

Taking the complex logarithm of both sides we have that

\[ \mathrm{Log}\,B_f(z)=\mathrm{Log}\,f(z) +\sum_{\rho\in\mathcal{K}_f(r)}m_f(\rho)\,\mathrm{Log}(R-z\overline{\rho}/R) -\sum_{\rho\in\mathcal{K}_f(r)}m_f(\rho)\,\mathrm{Log}(z-\rho). \]

Taking the derivative of both sides we have that

\[ \frac{B_f'}{B_f}(z)=\frac{f'}{f}(z) +\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-R^2/\overline{\rho}} -\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-\rho}. \]

By Definition JBlaschke and Theorem LogOfAnalyticFunction, since \(L_f(z)=J_{B_f}(z)\) we have \(L_f'(z)=J'_{B_f}(z)=(B_f'/B_f)(z)\). Thus,

\[ \frac{f'}{f}(z)-\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-\rho} =L_f'(z)-\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-R^2/\overline{\rho}}. \]

Now since \(z\in\overline{\mathbb{D}_{r'}}\subseteq\overline{\mathbb{D}_{R'}}\) and \(\rho\in\mathcal{K}_f(r)\subseteq\mathcal{K}_f(R')\), we know that \(R^2/R'-R'\leq|z-R^2/\overline{\rho}|\). Thus by the triangle inequality we have

\[ \left|\frac{f'}{f}(z)-\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-\rho}\right| \leq|L_f'(z)|+\left(\frac{1}{R^2/R'-R'}\right)\sum_{\rho\in\mathcal{K}_f(r)}m_f(\rho). \]

Now by Theorem ZerosBound and JBlaschkeDerivBound we get our desired result with a little algebraic manipulation.

Lean

Formalized as FinalBound.

Sources
Uses 10 · Used by 1

TheoremZetaFixedLowerBound#

For all \(t\in\mathbb{R}\) one has

\[ |\zeta(3/2+it)|\geq\frac{\zeta(3)}{\zeta(3/2)}. \]
Proof

From the Euler product expansion of \(\zeta\), we have that for \(\Re s>1\)

\[ \zeta(s)=\prod_p\frac{1}{1-p^{-s}}. \]

Thus, we have that

\[ \frac{\zeta(2s)}{\zeta(s)}=\prod_p\frac{1-p^{-s}}{1-p^{-2s}}=\prod_p\frac{1}{1+p^{-s}}. \]

Now note that \(|1-p^{-(3/2+it)}|\leq 1+|p^{-(3/2+it)}|=1+p^{-3/2}\). Thus,

\[ |\zeta(3/2+it)|=\prod_p\frac{1}{|1-p^{-(3/2+it)}|} \geq\prod_p\frac{1}{1+p^{-3/2}}=\frac{\zeta(3)}{\zeta(3/2)} \]

for all \(t\in\mathbb{R}\) as desired.

Lean

Formalized as ZetaFixedLowerBound.

Sources
Used by 2

DefinitionriemannZeta1#

Let

\[ \zeta_1(s)=1+\frac{1}{s-1}-s\int_1^\infty\{x\}\,x^{-s}\,\frac{dx}{x}. \]
Lean

Formalized as riemannZeta1.

Sources
Used by 3

TheoremZeta1AltFormula#

We have that

\[ \zeta_1(s)=\zeta_0(1,s) \]

where \(\zeta_0(1,s)\) comes from Definition riemannZeta0.

Proof

Note that

\[ \zeta_0(1,s)=1+\frac{-1}{1-s}+\frac{-1}{2}+ s\int_1^\infty\frac{\lfloor x\rfloor+1/2-x}{x^{s+1}}\,dx. \]

With minor simplifications we have

\[ \zeta_0(1,s)=1+\frac{1}{s-1}-\frac{1}{2}+ \frac{s}{2}\int_1^\infty x^{-s-1}\,dx-s\int_1^\infty\{x\}\,x^{-s-1}\,dx. \]

The first integral evaluates to \(1/s\) (when \(0\lt \mathfrak{R}s\)), so this term when multiplied by the \(s/2\) cancels with the \(-1/2\). This exactly gives \(\zeta_1\).

Lean

Formalized as Zeta1AltFormula.

Sources
Uses 2 · Used by 1
Statement usesriemannZeta1 · riemannZeta0

TheoremZetaAltFormula#

We have that

\[ \zeta(s)=\zeta_1(s) \]

for all \(s\in S\) with \(S=\{s\in\mathbb{C}:0\lt \mathfrak{R}s,\,s\neq 1\}\).

Proof

This immediately follows from Lemmas Zeta1AltFormula and Zeta0EqZeta.

Lean

Formalized as ZetaAltFormula.

Sources
Uses 4 · Used by 1
Statement usesriemannZeta1

TheoremGlobalBound#

For all \(s\in\mathbb{C}\) with \(|s|\leq 1\) and \(t\in\mathbb{R}\) with \(|t|\geq 2\), we have that

\[ |\zeta(s+3/2+it)|\leq 7+2\,|t|. \]
Proof

For the sake of clearer proof writing let \(z=s+3/2+it\). Since \(|s|\leq 1\) we know that \(1/2\leq\mathfrak{R}z\); additionally, as \(|t|\geq 2\), we know \(1\leq|\mathfrak{I}z|\). So, \(z\in S\). Thus, from Lemma ZetaAltFormula we know that

\[ |\zeta(z)|\leq 1+\frac{1}{|z-1|} +|z|\cdot\left|\int_1^\infty\{x\}\,x^{-z}\,\frac{dx}{x}\right| \]

by applying the triangle inequality. Now note that \(|z-1|\geq 1\). Likewise,

\[ |z|\cdot\left|\int_1^\infty\{x\}\,x^{-z}\,\frac{dx}{x}\right| \leq|z|\int_1^\infty|\{x\}\,x^{-z-1}|\,dx \leq|z|\int_1^\infty x^{-\Re z-1}\,dx=\frac{|z|}{\Re z}\leq 2\,|z|. \]

Thus we have that,

\[ |\zeta(s+3/2+it)|=|\zeta(z)|\leq 1+1+2\,|z|=2+2\,|s+3/2+it| \leq2+2\,|s|+3+2\,|it|\leq 7+2\,|t|. \]
Lean

Formalized as GlobalBound.

Sources
Uses 2 · Used by 2

Theoremnorm-zeta-strict-mono-ofReal#

If \(a,b\in\mathbb{R}\) with \(1\lt b\lt a\), then

\[ |\zeta(a)|<|\zeta(b)|. \]
Proof

Expand out \(\zeta\) as a summation (we can do this as we are in the region of convergence) and ignore the norm as every term is positive and real. Comparing term by term proves the result.

Lean

Formalized as norm_zeta_strict_mono_ofReal.

Sources
Used by 2

TheoremLogDerivZetaFinalBound#

Let \(t\in\mathbb{R}\) with \(|t|\geq 2\) and \(0 < r' < r < R' < R<1\). If \(f(z)=\zeta(z+3/2+it)\), then for all \(z\in\overline{\mathbb{D}_{r'}}\setminus\mathcal{K}_f(R')\) we have that

\[ \left|\frac{f'}{f}(z)-\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-\rho}\right| \ll\left(\frac{16r^2}{(r-r')^3}+\frac{1}{(R^2/R'-R')\,\log(R/R')}\right)\log|t|. \]
Proof

Let \(g(z)=\zeta(z+3/2+it)/\zeta(3/2+it)\). Note that \(g(0)=1\) and for \(|z|\leq R\)

\[ |g(z)|=\frac{|\zeta(z+3/2+it)|}{|\zeta(3/2+it)|} \leq\frac{\zeta(3/2)}{\zeta(3)}\cdot(7+2\,|t|)\leq\frac{13\,\zeta(3/2)}{3\,\zeta(3)}\,|t| \]

by Theorems ZetaFixedLowerBound and GlobalBound. Thus by Theorem FinalBound we have that

\[ \left|\frac{g'}{g}(z)-\sum_{\rho\in\mathcal{K}_g(r)}\frac{m_g(\rho)}{z-\rho}\right| \leq\left(\frac{16r^2}{(r-r')^3}+\frac{1}{(R^2/R'-R')\,\log(R/R')}\right) \left(\log|t|+\log\left(\frac{13\,\zeta(3/2)}{3\,\zeta(3)}\right)\right). \]

Now note that \(f'/f=g'/g\), \(\mathcal{K}_f(r)=\mathcal{K}_g(r)\), and \(m_g(\rho)=m_f(\rho)\) for all \(\rho\in\mathcal{K}_f(r)\). Thus we have that,

\[ \left|\frac{f'}{f}(z)-\sum_{\rho\in\mathcal{K}_f(r)}\frac{m_f(\rho)}{z-\rho}\right| \ll\left(\frac{16r^2}{(r-r')^3}+\frac{1}{(R^2/R'-R')\,\log(R/R')}\right)\log|t| \]

where the implied constant \(C\) is taken to be

\[ C\geq 1+\frac{\log(11\,\zeta(3/2)/\zeta(3))}{\log 2}. \]
Lean

Formalized as LogDerivZetaFinalBound.

Sources
Uses 5 · Used by 2

TheoremZetaShiftFiniteZeros#

For all \(|t|\geq 2\), if \(f(z)=\zeta(z+3/2+it)\), then \(f(z)\) has a finite number of zeros in \(\overline{\mathbb{D}_1}\).

Proof

If we suppose the opposite, i.e. that there are an infinite number of zeros in this region, then \(f\equiv 0\) by the identity theorem. This is a contradiction, so the statement must be true.

Lean

Formalized as ZetaShiftFiniteZeros.

Sources
Uses 1 · Used by 3

DefinitionZeroWindow#

Let \(\mathcal{Z}_t=\{\rho\in\mathbb{C}:\zeta(\rho)=0,\,|\rho-(3/2+it)|\leq 3/4\}\).

Lean

Formalized as ZeroWindow.

Sources
Used by 8

TheoremSumBoundI#

For all \(\delta\in (0,1)\) and \(t\in\mathbb{R}\) with \(|t|\geq 2\) we have

\[ \left|\frac{\zeta'}{\zeta}(1+\delta+it) -\sum_{\rho\in\mathcal{Z}_t}\frac{m_\zeta(\rho)}{1+\delta+it-\rho}\right|\ll\log|t|. \]
Proof

We apply Theorem LogDerivZetaFinalBound where \(r'=2/3\), \(r=3/4\), \(R'=4/5\), and \(R=5/6\). Thus, for all \(z\in\overline{\mathbb{D}_{2/3}}\setminus\mathcal{K}_f(4/5)\) we have that

\[ \left|\frac{\zeta'}{\zeta}(z+3/2+it) -\sum_{\rho\in\mathcal{K}_f(3/4)}\frac{m_f(\rho)}{z-\rho}\right|\ll\log|t| \]

where \(f(z)=\zeta(z+3/2+it)\) for \(t\in\mathbb{R}\) with \(|t|\geq 2\). Now if we let \(z=-1/2+\delta\), then \(z\in(-1/2,1/2)\subseteq\overline{\mathbb{D}_{2/3}}\). Additionally, \(f(z)=\zeta(1+\delta+it)\), where \(1+\delta+it\) lies in the zero-free region where \(\sigma>1\). Thus, \(z\not\in\mathcal{K}_f(4/5)\). So,

\[ \left|\frac{\zeta'}{\zeta}(1+\delta+it) -\sum_{\rho\in\mathcal{K}_f(3/4)}\frac{m_f(\rho)}{-1/2+\delta-\rho}\right| \ll\log|t|. \]

But now note that if \(\rho\in\mathcal{K}_f(3/4)\), then \(\zeta(\rho+3/2+it)=0\) and \(|\rho|\leq 3/4\). Thus, \(\rho+3/2+it\in\mathcal{Z}_t\) (the argument works in reverse as well). Additionally, note that \(m_f(\rho)=m_\zeta(\rho+3/2+it)\). So changing variables using these facts gives us that

\[ \left|\frac{\zeta'}{\zeta}(1+\delta+it) -\sum_{\rho\in\mathcal{Z}_t}\frac{m_\zeta(\rho)}{1+\delta+it-\rho}\right| \ll\log|t|. \]
Lean

Formalized as SumBoundI.

Sources
Uses 4 · Used by 2

TheoremShiftTwoBound#

For all \(\delta\in (0,1)\) and \(t\in\mathbb{R}\) with \(|t|\geq 2\) we have

\[ -\Re \left(\frac{\zeta'}{\zeta}(1+\delta+2it)\right)\ll\log|t|. \]
Proof

Note that, for \(\rho\in\mathcal{Z}_{2t}\)

\[ \begin{aligned} \Re \left(\frac{1}{1+\delta+2it-\rho}\right) &=\Re \left(\frac{1+\delta-2it-\overline{\rho}} {(1+\delta+2it-\rho)(1+\delta-2it-\overline{\rho})}\right) \\ &=\frac{\Re (1+\delta-2it-\overline{\rho})}{|1+\delta+2it-\rho|^2} =\frac{1+\delta-\Re \rho}{(1+\delta-\Re \rho)^2+(2t-\mathfrak{I}\rho)^2}. \end{aligned} \]

Now since \(\rho\in\mathcal{Z}_{2t}\), we have that \(|\rho-(3/2+2it)|\leq 3/4\). So, we have \(\Re \rho\in[3/4,9/4]\) and \(\mathfrak{I}\rho\in[2t-3/4,2t+3/4]\). Additionally, we know that \(\zeta(\rho)=0\). This implies the stronger condition that \(\Re \rho\in[3/4,1]\). Thus,

\[ \delta\leq 1+\delta-\Re \rho\qquad\text{and}\qquad (1+\delta-\Re \rho)^2+(2t-\mathfrak{I}\rho)^2\leq 25/16+9/16=17/8. \]

Which implies that

\[ 0\lt \frac{8}{17}\,\delta \leq\frac{1+\delta-\Re \rho}{(1+\delta-\Re \rho)^2+(2t-\mathfrak{I}\rho)^2} =\Re \left(\frac{1}{1+\delta+2it-\rho}\right).\qquad\text{(4)} \]

Note that, from Lemma SumBoundI, we have

\[ \sum_{\rho\in\mathcal{Z}_{2t}}m_\zeta(\rho)\, \Re \left(\frac{1}{1+\delta+2it-\rho}\right) -\Re \left(\frac{\zeta'}{\zeta}(1+\delta+2it)\right) \leq\left|\frac{\zeta'}{\zeta}(1+\delta+2it) -\sum_{\rho\in\mathcal{Z}_{2t}}\frac{m_\zeta(\rho)}{1+\delta+2it-\rho}\right| \ll\log|2t|. \]

Since \(m_\zeta(\rho)\geq 0\) for all \(\rho\in\mathcal{Z}_{2t}\), the inequality from Equation (4) tells us that by subtracting the sum from both sides we have

\[ -\Re \left(\frac{\zeta'}{\zeta}(1+\delta+2it)\right)\ll\log|2t|. \]

Noting that \(\log|2t|=\log(2)+\log|t|\leq2\log|t|\) completes the proof.

Lean

Formalized as ShiftTwoBound.

Sources
Uses 2 · Used by 1
Statement usesZeroWindow
Proof usesSumBoundI

TheoremShiftOneBound#

There exists \(C>0\) such that for all \(\delta\in(0,1)\) and \(t\in\mathbb{R}\) with \(|t|\geq 2\); if \(\zeta(\rho)=0\) with \(\rho=\sigma+it\), then

\[ -\Re \left(\frac{\zeta'}{\zeta}(1+\delta+it)\right) \leq -\frac{1}{1+\delta-\sigma}+C\log|t|. \]
Proof

Note that for \(\rho'\in\mathcal{Z}_t\)

\[ \begin{aligned} \mathfrak{R}\left(\frac{1}{1+\delta+it-\rho'}\right)&=\mathfrak{R}\left( \frac{1+\delta-it-\overline{\rho'}}{(1+\delta+it-\rho')(1+\delta-it-\overline{\rho'})}\right) \\ &=\frac{\mathfrak{R}(1+\delta-it-\overline{\rho'})}{|1+\delta+it-\rho'|^2} =\frac{1+\delta-\mathfrak{R}\rho'}{(1+\delta-\mathfrak{R}\rho')^2+(t-\mathfrak{I}\rho')^2}. \end{aligned} \]

Now since \(\rho'\in\mathcal{Z}_t\), we have that \(|\rho'-(3/2+it)|\leq 3/4\). So, we have \(\mathfrak{R}\rho'\in[3/4,9/4]\) and \(\mathfrak{I}\rho'\in[t-3/4,t+3/4]\). Additionally, we know that \(\zeta(\rho')=0\). This implies the stronger condition that \(\mathfrak{R}\rho'\in[3/4,1]\). Thus,

\[ \delta\leq 1+\delta-\mathfrak{R}\rho' \qquad\text{and}\qquad (1+\delta-\mathfrak{R}\rho')^2+(t-\mathfrak{I}\rho')^2\leq 25/16+9/16=17/8. \]

Which implies that

\[ 0\lt \frac{8}{17}\,\delta\leq\frac{1+\delta-\mathfrak{R}\rho'}{(1+\delta-\mathfrak{R}\rho')^2 +(t-\mathfrak{I}\rho')^2}=\mathfrak{R}\left(\frac{1}{1+\delta+it-\rho'}\right).\qquad\text{(5)} \]

Note that, from Lemma SumBoundI, we have

\[ \sum_{\rho'\in\mathcal{Z}_t}m_\zeta(\rho')\,\mathfrak{R}\left( \frac{1}{1+\delta+it-\rho'}\right)-\mathfrak{R}\left( \frac{\zeta'}{\zeta}(1+\delta+it)\right)\leq \left|\frac{\zeta'}{\zeta}(1+\delta+it) -\sum_{\rho'\in\mathcal{Z}_t}\frac{m_\zeta(\rho')}{1+\delta+it-\rho'}\right|\ll\log|t|. \]

Now we proceed via cases. If \(\rho\in\mathcal{Z}_t\), then \(\mathcal{Z}_t=\rho\sqcup(\mathcal{Z}_t\setminus\rho)\) and the inequality from Equation (5) tells us that by subtracting the sum over all \(\rho'\in\mathcal{Z}_t\setminus\{\rho\}\) from both sides we have

\[ \frac{m_\zeta(\rho)}{\mathfrak{R}(1+\delta+it-\rho)} -\mathfrak{R}\left(\frac{\zeta'}{\zeta}(1+\delta+it)\right)\ll\log|t|. \]

But of course we have that \(\mathfrak{R}(1+\delta+it-\rho)=1+\delta-\sigma\). So subtracting this term from both sides and recalling the implied constant we have

\[ -\mathfrak{R}\left(\frac{\zeta'}{\zeta}(1+\delta+it)\right)\leq -\frac{m_\zeta(\rho)}{1+\delta-\sigma}+C\log|t|. \]

We have that \(\sigma\leq 1\) since \(\zeta\) is zero free on the right half plane \(\sigma>1\). Thus, \(0<1+\delta-\sigma\). Noting this in combination with the fact that \(1\leq m_\zeta(\rho)\) gives us that

\[ -\mathfrak{R}\left(\frac{\zeta'}{\zeta}(1+\delta+it)\right)\leq -\frac{m_\zeta(\rho)}{1+\delta-\sigma}+C\log|t|\leq-\frac{1}{1+\delta-\rho}+(7+C)\log|t|. \]

Now if \(\rho\not\in\mathcal{Z}_t\), then \(|\sigma-3/2|=|\rho-(3/2+it)|>3/4\) since \(\zeta(\rho)=0\). Additionally, \(\sigma\leq 1\) since \(\zeta(\rho)=0\), thus \(3/2-\sigma=|\sigma-3/2|>3/4\). So it follows that

\[ \frac{1}{1+\delta-\sigma}<4<7\log 2\leq 7\log|t|. \]

Thus, by subtracting the sum over \(\rho'\in\mathcal{Z}_t\) from both sides we have

\[ -\mathfrak{R}\left(\frac{\zeta'}{\zeta}(1+\delta+it)\right)\leq C\log|t|\leq-\frac{1}{1+\delta-\rho}+(7+C)\log|t|. \]
Lean

Formalized as ShiftOneBound.

Sources
Uses 2 · Used by 1
Statement usesZeroWindow
Proof usesSumBoundI

TheoremShiftZeroBound#

For all \(\delta\in(0,1)\) we have

\[ -\Re \left(\frac{\zeta'}{\zeta}(1+\delta)\right)\leq\frac{1}{\delta}+O(1). \]
Proof

From Theorem riemannZetaLogDerivResidue we know that

\[ -\frac{\zeta'}{\zeta}(s)=\frac{1}{s-1}+O(1). \]

Changing variables \(s\mapsto 1+\delta\) and applying the triangle inequality we have that

\[ -\Re \left(\frac{\zeta'}{\zeta}(1+\delta)\right)\leq\left| -\frac{\zeta'}{\zeta}(1+\delta)\right|\leq\frac{1}{\delta}+O(1). \]
Lean

Formalized as ShiftZeroBound.

Sources
Uses 2 · Used by 1

TheoremvonMangoldtLSeriesSummable#

The series

\[ \sum_{n=1}^\infty\frac{\Lambda(n)}{n^s} \]

converges when \(1\lt \mathfrak{R}(s)\).

Proof

We know that \(\Lambda(n)\) is \(O(n^\varepsilon)\) since it is bounded above by \(\log(n)\). Thus,

\[ \left|\sum_{n=1}^\infty\frac{\Lambda(n)}{n^s}\right|\leq \sum_{n=1}^\infty\left|\frac{\Lambda(n)}{n^s}\right|\ll \sum_{n=1}^\infty\frac{1}{n^{\mathfrak{R}(s)-\varepsilon}}. \]

Since \(\varepsilon\) can be arbitrarily small, we know the left hand side converges by the \(p\)-test.

Lean

Formalized as vonMangoldtLSeriesSummable.

Sources
Used by 2

TheoremZeroWindowFinite#

For all \(|t|\geq 2\), \(\mathcal{Z}(t)\) contains a finite number of points.

Proof

If we suppose the opposite, i.e. that there are an infinite number of zeta zeros in this region, then \(\zeta\equiv 0\) by the identity theorem. This is a contradiction, so the statement must be true.

Lean

Formalized as ZeroWindowFinite.

Sources
Uses 1 · Used by 2

TheoremZeroInequality#

There exists a constant \(0 < E<1/14\) such that for all \(\rho=\sigma+it\) with \(\zeta(\rho)=0\) and \(|t|\geq 2\), one has

\[ \sigma\leq 1-\frac{E}{\log|t|}. \]
Proof

From Theorem LogDerivativeDirichlet when \(\Re s>1\) we have

\[ -\frac{\zeta'}{\zeta}(s)=\sum_{1\leq n}\frac{\Lambda(n)}{n^s}. \]

Thus,

\[ -3\,\frac{\zeta'}{\zeta}(1+\delta) -4\,\frac{\zeta'}{\zeta}(1+\delta+it) -\frac{\zeta'}{\zeta}(1+\delta+2it) =\sum_{1\leq n}\Lambda(n)\,n^{-(1+\delta)}\left(3+4n^{-it}+n^{-2it}\right). \]

Now applying Euler's identity

\[ \begin{aligned} -3\,\Re \left(\frac{\zeta'}{\zeta}(1+\delta)\right)& -4\,\Re \left(\frac{\zeta'}{\zeta}(1+\delta+it)\right) -\Re \left(\frac{\zeta'}{\zeta}(1+\delta+2it)\right) \\ &\qquad\qquad\qquad=\sum_{1\leq n}\Lambda(n)\,n^{-(1+\delta)} \left(3+4\cos(-t\log n)+\cos(-2t\log n)\right) \end{aligned} \]

Since

\[ 3+4\cos(-t\log n)+\cos(-2t\log n)=2\,(1+\cos(-t\log n))^2\geq 0, \]

we know that the series on the right hand side is bounded below by \(0\), and by Lemmas ShiftTwoBound, ShiftOneBound, and ShiftZeroBound we have an upper bound on the left hand side. So,

\[ 0\leq\frac{3}{\delta}+3A-\frac{4}{1+\delta-\sigma}+4B\log|t|+C\log|t| \]

where \(A\), \(B\), and \(C\) are the implied constants coming from Lemmas ShiftZeroBound, ShiftOneBound, and ShiftTwoBound respectively. By choosing \(D\geq 5A+4B+C\geq 3A/\log 2+4B+C\) we have

\[ \frac{4}{1+\delta-\sigma}\leq\frac{3}{\delta}+D\log|t| \]

by some manipulation. Now if we choose \(\delta=(2D\log|t|)^{-1}\) then we have

\[ \frac{4}{1-\sigma+1/(2D\log|t|)}\leq7D\log|t|. \]

So with some manipulation we have that

\[ \sigma\leq 1-\frac{1}{14D\log|t|}. \]

This is exactly the desired result with the constant \(E=(14D)^{-1}\). Since \(D\geq 5A+4B+C\geq 1\) we have that \(E\in(0,1/14)\).

Lean

Formalized as ZeroInequality.

Sources
Uses 7 · Used by 7

DefinitionDeltaT#

Let \(\delta_t=E/\log|t|\) where \(E\) is the constant coming from Theorem ZeroInequality.

Lean

Formalized as DeltaT.

Sources
LeanDeltaT
Uses 1 · Used by 4

TheoremDeltaRange#

For all \(t\in\mathbb{R}\) with \(|t|\geq 2\) we have that

\[ \delta_t<1/9. \]
Proof

Note that \(\delta_t=E/\log|t|\) where \(E\) is the implied constant from Lemma ZeroInequality. But we know that \(E=(14D)^{-1}\) where \(D\geq 5A+4B+C\) where \(A\), \(B\), and \(C\) are the constants coming from Lemmas ShiftZeroBound, ShiftOneBound, and ShiftTwoBound respectively. Thus,

\[ E\leq\frac{1}{14\,(5A+4B+C)}. \]

But note that \(A\geq 1\), \(B>0\), and \(C>0\) by Lemmas ShiftZeroBound, ShiftOneBound, and ShiftTwoBound respectively. So, by a very lazy estimate we have \(E\leq 1/14\). Thus,

\[ \delta_t=\frac{E}{\log|t|}\leq\frac{1}{14\,\log2}\lt \frac{1}{9}. \]
Lean

Formalized as DeltaRange.

Sources
Uses 2 · Used by 1
Statement usesDeltaT
Proof usesZeroInequality
Used bySumBoundII

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