9 Primary explicit estimates
9.1 Definitions
In this section we define the basic types of primary estimates we will work with in the project.
9.2 A Lemma involving the Möbius Function
In this section we establish a lemma involving sums of the Möbius function.
\(Q(x)\) is the number of squarefree integers \(\leq x\).
\(R(x) = Q(x) - x / \zeta (2)\).
\(M(x)\) is the summatory function of the Möbius function.
For any \(x{\gt}0\),
.
We compute
giving the claim.
For any \(x{\gt}0\),
The equality is immediate from Theorem 9.2.1 and exchanging the order of \(\sum \) and \(\int \), as is justified by \(\sum _n |\mu (n)|\int _0^{x/n^2} du \leq \sum _n x/n^2 {\lt} \infty \))
Since our sums start from \(1\), the sum \(\sum _{k\leq K}\) is empty for \(K=0\).
For any \(K \leq x\),
This is just splitting the sum at \(K\).
For any \(K \leq x\), for \(f(u) = M(\sqrt{x/u})\),
This is just splitting the integral at \(K\), since \(f(u) = M(\sqrt{x/u}) = 0\) for \(x{\gt}u\).
For any \(x{\gt}0\) and any integer \(K\geq 0\),
9.3 The estimates of Fiori, Kadiri, and Swidinsky
In this section we establish the primary results of Fiori, Kadiri, and Swidinsky [ 23 ] .
TODO: reorganize this blueprint and add proofs.
Let \(H_0\) denote a verification height for RH. Let \(10^9/H_0≤ k \leq 1\), \(t {\gt} 0\), \(H \in [1002, H_0)\), \(α {\gt} 0\), \(δ ≥ 1\), \(\eta _0 = 0.23622\), \(1 + \eta _0 \leq \mu \leq 1+\eta \), and \(\eta \in (\eta _0, 1/2)\) be fixed. Let \(\sigma {\gt} 1/2 + d / \log H_0\). Then for any \(T \geq H_0\), one has
and
.
The previous bounds hold for \((\sigma , \alpha , \delta , d, CC_1, c_1, CC_2, c_2)\) given by Table 7 and Table 7’ of the paper.
For each \(\sigma _1, \sigma _2, \tilde c_1, \tilde c_2\) given in Table 8, we have \(N(\sigma ,T) \leq \tilde c_1 T^{p(\sigma )} \log ^{q(\sigma )} + \tilde c_2 \log ^2 T\) for \(\sigma _1 \leq \sigma \leq \sigma _2\) with \(p(\sigma ) = 8/3 (1-\sigma )\) and \(q(σ) = 5-2\sigma \).
If \(|N(T) - (T/2\pi \log (T/2\pi e) + 7/8)| \leq R(T)\) then \(\sum _{U \leq \gamma {\lt} V} 1/\gamma \leq B_1(U,V)\).
For each pair \(T_0,S_0\) in Table 1 we have, for all \(V {\gt} T_0\), \(\sum _{0 {\lt} \gamma {\lt} V} 1/\gamma {\lt} S_0 + B_1(T_0,V)\).
Let \(T_0 \geq 2\) and \(\gamma {\gt} 0\). Assume that there exist \(c_1, c_2, p, q, T_0\) for which one has a zero density bound. Assume \(\sigma \geq 5/8\) and \(T_0 \leq U {\lt} V\). Then \(s_0(σ,U,V) \leq B_0(\sigma ,U,V)\).
\(\Gamma (3,x) = (x^2 + 2(x+1)) e^{-x}\).
For \(s{\gt}1\), one has \(\Gamma (s,x) \sim x^{s-1} e^{-x}\).
Let \(x {\gt} e^{50}\) and \(50 {\lt} T {\lt} x\). Then \(E_\psi (x) \leq \sum _{|\gamma | {\lt} T} |x^{\rho -1}/\rho | + 2 \log ^2 x / T\).
For any \(\alpha \in (0,1/2]\) and \(\omega \in [0,1]\) there exist \(M, x_M\) such that for \(\max (51, \log x) {\lt} T {\lt} (x^\alpha -2)/5\) and some \(T^* \in [T, 2.45 T]\),
for all \(x ≥ x_M\).
Let \(x {\gt} e^{50}\) and \(3 \log x {\lt} T {\lt} \sqrt{x}/3\). Then \(E_\psi (x) ≤ \sum _{|\gamma | {\lt} T} |x^{\rho -1}/\rho | + 2 \log ^2 x / T\).
Let \(\sigma _1 \in (1/2,1)\) and let \((T_0,S_0)\) be taken from Table 1. Then \(\Sigma _0^{\sigma _1} ≤ 2 x^{-1/2} (S_0 + B_1(T_0,T)) + (x_1^{\sigma _1-1} - x^{-1/2}) B_1(H_0,T)\).
\(\Sigma _a^b = 2 * \sum _{H_a ≤ \gamma {\lt} T; a \leq \beta {\lt} b} \frac{x^{\beta -1}}{\gamma }\).
If \(H_0 {\gt} 1\), \(R {\gt} 0\), and \(\sigma {\lt} 1 - 1/(R \log H_0)\), then \(H_σ = H_0\).
Let \(N \geq 2\) be an integer. If \(5/8 \leq \sigma _1 {\lt} \sigma _2 \leq 1\), \(T \geq H_0\), then \(\Sigma _{\sigma _1}^{\sigma _2} ≤ 2 x^{-(1-\sigma _1)+(\sigma _2-\sigma _1/N)}B_0(\sigma _1, H_{\sigma _1}, T) + 2 x^{(1-\sigma _1)} (1 - x^{-(\sigma _2-\sigma _1)/N}) \sum _{n=1}^{N-1} B_0(\sigma ^{(n)}, H^{(n)}, T) x^{(\sigma _2-\sigma _1) (n+1)/N}\).
If \(\sigma _1 \geq 0.9\) then \(\Sigma _{\sigma _1}^{\sigma _2} \leq 0.00125994 x^{\sigma _2-1}\).
Let \(5/8 {\lt} \sigma _2 \leq 1\), \(t_0 = t_0(\sigma _2,x) = \max (H_{\sigma _2}, \exp ( \sqrt{\log x}/R))\) and \(T {\gt} 0\). Let \(K \geq 2\) and consider a strictly increasing sequence \((t_k)_{k=0}^K\) such that \(t_k = T\). Then \(\Sigma _{\sigma _2}^1 ≤ 2 N(\sigma _2,T) x^{-1/R\log t_0}/t_0\) and \(\Sigma _{\sigma _2}^1 ≤ 2 ((\sum _{k=1}^{K-1} N(\sigma _2, t_k) (x^{-1/R\log t_{k-1}} / t_{k-1} - x^{-1/(R \log t_k)}/t_k)) + x^{-1/R \log t_{K-1}}/t_{K-1} N(\sigma _2,T))\).
Let \(5/8 {\lt} \sigma _2 \leq 1\), \(t_0 = t_0(\sigma _2, x) = \max \left(H_{\sigma _2}, \exp \left(\sqrt{\frac{\log x}{R}}\right)\right)\), \(T {\gt} t_0\). Let \(K \geq 2\), \(\lambda = (T/t_0)^{1/K}\), and consider \((t_k)_{k=0}^K\) the sequence given by \(t_k = t_0 \lambda ^k\). Then
where
and \(\tilde{N}(\sigma , T)\) satisfy (ZDB) \(N(\sigma , T) \leq \tilde{N}(\sigma , T)\).
Fix \(K \geq 2\) and \(c {\gt} 1\), and set \(t_0\), \(T\), and \(\sigma _2\) as functions of \(x\) defined by
Then, with \(\varepsilon _4(x, \sigma _2, K, T)\) as defined in (3.22), we have that as \(x \to \infty \),
where \(c_1\) is an admissible value for (ZDB) on some interval \([\sigma _1, 1]\). Moreover, both \(\varepsilon _4(x, \sigma _2, K, T)\) and \(\frac{\varepsilon _4(x, \sigma _2, K, T) t_0^2}{(\log t_0)^3}\) are decreasing in \(x\) for \(x {\gt} \exp (Re^2)\).
For any \(x_0\) with \(\log x_0 {\gt} 1000\), and all \(0.9 {\lt} \sigma _2 {\lt} 1\), \(2 \leq c \leq 30\), and \(N, K \geq 1\) the formula \(\varepsilon (x_0) := \varepsilon (x_0, \sigma _2, c, N, K)\) as defined in (4.1) gives an effectively computable bound
Moreover, a collection of values, \(\varepsilon (x_0)\) computed with well chosen parameters are provided in Table 5.
For all \(0 {\lt} \log x \leq 2100\) we have that
For all \(2100 {\lt} \log x \leq 200000\) we have that
If \(\log x_0 \geq 1000\) then we have an admissible bound for \(E_\psi \) with the indicated choice of \(A(x_0)\), \(B = 3/2\), \(C = 2\), and \(R = 5.5666305\).
For all x > 2 we have \(E_ψ(x) \leq 9.22022(\log x)^{3/2} \exp (-0.8476836 \sqrt{\log x})\).
TODO.
For all x > 2 we have \(E_ψ(x) \leq 121.096 (\log x/R)^{3/2} \exp (-2 \sqrt{\log x/R})\) with \(R = 5.5666305\). This minor variant of Corollary 1.4 is not directly stated in this paper, but is stated in [ 24 , Remark 2 ] .
9.4 Numerical content of BKLNW Appendix A
Purely numerical calculations from Appendix A of [ 4 ] . This is kept in a separate file from the main file to avoid heavy recompilations. Because of this, this file should not import any other files from the PNT+ project, other than further numerical data files.
The value of \(\varepsilon (b)\) arising from Table 8 of [ 4 ] is weaker than that from the expanded version of Table 8 available in the arXiv.
Routine computation.
9.5 Appendix A of BKLNW
In this file we record the results from Appendix A of [ 4 ] . In this appendix, the authors derive explicit estimates on the error term in the prime number theorem for the Chebyshev function \(\psi \) assuming various inputs on the zeros of the Riemann zeta function, including a zero-density estimate, a classical zero-free region, and numerical verification of RH up to some height.
Let \(x \geq e^{1000}\) and \(T\) satisfies \(50 {\lt} T \leq x\). Then
where \(A = \mathcal{O}^*(B)\) means \(|A| \leq B\).
See [ 17 , Theorem 1.3 ] .
We denote
We denote
We denote
We have
Follows directly from the definitions of Σ₁ and Σ₂.
We have
See [ 44 , Lemma 2.10 ] .
We denote
We have
An argument of Pintz [ s employed. The interval \([0,T]\) is split into subintervals \([T/\lambda ^{k+1}, T/\lambda ^k]\) where \(\lambda {\gt} 1\), \(0 \leq k \leq K-1\), and \(K = \lfloor \frac{\log T/H}{\log \lambda } \rfloor + 1\). Then use the zero-free region to bound \(\Re \rho \).
We have
where \(p\), \(q\), \(c_1\), \(c_2\) are the parameters of the zero density bound.
Inserting (A.6) into the result of (A.12).
We denote
where \(p\), \(q\), \(c_1\), \(c_2\) are the parameters of the zero density bound.
Let \(b_1, b_2\) satisfy \(1000 \leq b_1 {\lt} b_2\). Let \(0.001 \leq \delta \leq 0.025\), \(\lambda {\gt} 1\), \(H {\lt} T {\lt} e^{b_1}\), and \(K = \left\lfloor \frac{\log \frac{T}{H}}{\log \lambda } \right\rfloor + 1\). Then for all \(x \in [e^{b_1}, e^{b_2}]\)
where \(s_0, s_1, s_2\) are respectively defined in Definitions 9.5.1, 9.5.4, and 9.5.5
Follows from combining Sublemmas ??, ??, ??, and ??.
We define
We define
We define
We define
We define
We define
and
This is proven by Platt and Trudgian [ 35 ]
For \(100 \leq x \leq 10^{19}\), one has
This follows from Theorem 10.6.1.
Let \(B_0\), \(B\), and \(c\) be positive constants such that
is known. Furthermore, assume for every \(b_0 {\gt} 0\) there exists \(\varepsilon (b_0) {\gt} 0\) such that
Let \(b\) be positive such that \(e^b \in (B_0, B]\). Then, for all \(x \geq e^b\) we have
Multiplying both sides of 6 by \(\frac{1}{\sqrt{x}}\) gives
as \(\frac{1}{\sqrt{x}} \leq \frac{1}{e^{\frac{b}{2}}}\). Then, for \(x \geq B\) we apply 7 with \(b_0 = \log B\). Combining these bounds, we derive 8.
Let \(b\) be a positive constant such that \(\log 11 {\lt} b \leq 19 \log (10)\). Then we have
Note that by Table 8, we have \(\varepsilon (19 \log 10) = 1.93378 \cdot 10^{-8}\).
We define Logan’s function
The Fourier transform \(\eta _{c,\varepsilon }(\xi ) = \frac{1}{2\pi } \int _{\mathbb {R}} e^{-it\xi } ℓ_{c,\varepsilon }(t) \, dt\) of Logan’s kernel, in closed form: the kernel is band-limited, so the transform is supported in \([-\varepsilon , \varepsilon ]\), where
with \(I_0\) the modified Bessel function of order zero ( [ 5 , p. 2490 ] ). The closed form is taken as the definition; the Fourier identity is a proof obligation of Theorem 16.
We define the auxiliary functions
Let \(0 {\lt} \varepsilon {\lt} 10^{-3}\), \(c \geq 3\), \(x_0 \geq 100\) and \(\alpha \in [0, 1)\) such that the inequality
holds. We denote the zeros of the Riemann zeta function by \(\rho = \beta + i\gamma \) with \(\beta , \gamma \in \mathbb {R}\). Then, if \(\beta = \frac{1}{2}\) holds for \(0 {\lt} \gamma \leq \frac{c}{\varepsilon }\), the inequality
holds for all \(x \geq e^{\varepsilon \alpha } x_0\), where
The \(\nu _c(\alpha ) = \nu _{c,1}(\alpha )\) and \(\mu _c(\alpha ) = \mu _{c,1}(\alpha )\) where \(\nu _{c,\varepsilon }(\alpha )\) and \(\mu _{c,\varepsilon }(\alpha )\) are defined by [ 5 , p. 2490 ] .
This is [ 5 , Theorem 1 ] .
Note: This thesis of Bhattacharjee [ 3 ] will be a good resource when formalizing this result.
If \(b{\gt}0\) then \(|\psi (x) - x| \leq \varepsilon (b) x\) for all \(x \geq \exp (b)\), where \(\varepsilon \) is as in [ 4 , Table 8 ] .
Let \(b\) be a positive constant such that \(\log 11 {\lt} b \leq 19 \log (10)\). Then we have
From Table 8 we have \(\varepsilon (19 \log 10) = 1.93378 \cdot 10^{-8}\). Now apply Corollary 9.5.1 and Theorem ??.
9.6 Chirre-Helfgott’s estimates for sums of nonnegative arithmetic functions
We record some estimates from [ 9 ] for summing non-negative functions, with a particular interest in estimating \(\psi \).
9.6.1 Fourier-analytic considerations
Some material from [ 9 , Section 2 ] , slightly rearranged to take advantage of existing results in the repository.
Let \(a_n\) be a sequence with \(\sum _{n{\gt}1} \frac{|a_n|}{n \log ^\beta n} {\lt} \infty \) for some \(\beta {\gt} 1\). Write \(G(s)= \sum _n a_n n^{-s} - \frac{1}{s-1}\) for \(\mathrm{Re} s {\gt} 1\). Let \(\varphi \) be absolutely integrable, supported on \([-1,1]\), and has Fourier decay \(\hat\psi (y) = O(1/|y|^\beta )\). Then for any \(x{\gt}0\) and \(\sigma {\gt} 1\)
Let \(a_n\) be a sequence with \(\sum _{n{\gt}1} \frac{|a_n|}{n \log ^\beta n} {\lt} \infty \) for some \(\beta {\gt} 1\). Assume that \(\sum _n a_n n^{-s} - \frac{1}{s-1}\) extends continuously to a function \(G\) defined on \(1 + i[-T,T]\). Let \(\varphi \) be absolutely integrable, supported on \([-1,1]\), and has Fourier decay \(\hat\varphi (y) = O(1/|y|^\beta )\). Then for any \(x{\gt}0\),
Apply Sublemma 9.6.1 and take the limit as \(\sigma \to 1^+\), using the continuity of \(G\) and the dominated convergence theorem, as well as the Fourier inversion formula.
\(S_\sigma (x)\) is equal to \(\sum _{n \leq x} a_n / n^\sigma \) if \(\sigma {\lt} 1\) and \(\sum _{n \geq x} a_n / n^\sigma \) if \(\sigma {\gt} 1\).
\(I_\lambda (u) = 1_{[0,\infty )}(\mathrm{sgn}(\lambda )u) e^{-\lambda u}\).
\(S_\sigma (x) = x^{-\sigma } \sum _n a_n \frac{x}{n} I_\lambda ( \frac{T}{2\pi } \log \frac{n}{x} )\) where \(\lambda = 2\pi (\sigma -1)/T\).
Routine manipulation.
Let \(a_n\) be a non-negative sequence with \(\sum _{n{\gt}1} \frac{|a_n|}{n \log ^\beta n} {\lt} \infty \) for some \(\beta {\gt} 1\). Assume that \(\sum _n a_n n^{-s} - \frac{1}{s-1}\) extends continuously to a function \(G\) defined on \(1 + i[-T,T]\). Let \(\varphi _+\) be absolutely integrable, supported on \([-1,1]\), and has Fourier decay \(\hat\varphi _+(y) = O(1/|y|^\beta )\). Let \(\sigma \neq 1\) and write \(\lambda = 2\pi (\sigma -1)/T\). Assume \(I_\lambda (y) \leq \hat\varphi _+(y)\) for all \(y\). Then for any \(x\geq 1\),
By the nonnegativity of \(a_n\) we have
By Proposition 9.6.1 we can express the right-hand side as
If \(\lambda {\gt} 0\), then \(I_\lambda (y)=0\) for negative \(y\), so
If \(\lambda {\lt} 0\), then \(I_\lambda (y)=e^{-\lambda y}\) for \(y\) negative, so
hence
Since \(x^{-\sigma } * (2\pi x / T) * x^{\sigma -1}/(-\lambda ) = 1/(1-\sigma )\), the result follows.
Let \(a_n\) be a non-negative sequence with \(\sum _{n{\gt}1} \frac{|a_n|}{n \log ^\beta n} {\lt} \infty \) for some \(\beta {\gt} 1\). Assume that \(\sum _n a_n n^{-s} - \frac{1}{s-1}\) extends continuously to a function \(G\) defined on \(1 + i[-T,T]\). Let \(\varphi _-\) be absolutely integrable, supported on \([-1,1]\), and has Fourier decay \(\hat\varphi _-(y) = O(1/|y|^\beta )\). Let \(\sigma \neq 1\) and write \(\lambda = 2\pi (\sigma -1)/T\). Assume \(\hat\varphi _-(y) \leq I_\lambda (y)\) for all \(y\). Then for any \(x\geq 1\) and \(\sigma \neq 1\),
9.6.2 Extremal approximants to the truncated exponential
In this section we construct extremal approximants to the truncated exponential function and establish their basic properties, following [ 9 , Section 4 ] , although we skip the proof of their extremality. As such, the material here is organized rather differently from that in the paper.
where
is meromorphic.
This follows from the definition of \(\Phi ^{\pm ,\circ }_\nu \) and the properties of the \(\coth \) function.
The poles of
are of the form \(n - i \nu /2\pi \) for \(n \in \mathbb {Z}\).
This follows from the definition of \(\Phi ^{\pm ,\circ }_\nu \) and the properties of the \(\coth \) function.
The residue of
at \(n - i \nu /2\pi \) is \(i/2\pi \).
This follows from the definition of \(\Phi ^{\pm ,\circ }_\nu \) and the properties of the \(\coth \) function.
The poles of
are all simple.
This follows from the definition of \(\Phi ^{\pm ,\circ }_\nu \) and the properties of the \(\coth \) function.
\(B^\pm (s) = s/2 (\coth (s/2) \pm 1)\) with the convention \(B^\pm (0) = 1\).
\(B^\pm \) is continuous at \(0\).
L’Hôpital’s rule can be applied to show the continuity at \(0\).
where
This follows from the definition of \(B^\pm \) and the fact that \(B^\pm (0) = 1\).
is meromorphic.
This follows from the definition of \(\Phi ^{\pm ,\ast }_\nu \) and the properties of the \(B^\pm \) function.
The poles of
are of the form \(n - i \nu /2\pi \) for \(n \in \mathbb {Z} \backslash \{ 0\} \).
This follows from the definition of \(\Phi ^{\pm ,\ast }_\nu \) and the properties of the \(B^\pm \) function.
The residue of
at \(n - i \nu /2\pi \) is \(-in/2\pi \).
This follows from the definition of \(\Phi ^{\pm ,\ast }_\nu \) and the properties of the \(B^\pm \) function.
The poles of
are all simple.
This follows from the definition of \(\Phi ^{\pm ,\ast }_\nu \) and the properties of the \(B^\pm \) function.
\(\Phi ^{\sigma , \circ }_\nu (z) \pm \Phi ^{\sigma , \ast }_\nu (z)\) is regular at \(\pm 1 - i \nu / 2 \pi \).
The residues cancel out.
\(\varphi \) is \(C^2\) on \([-1,0]\).
Since \(\Phi ^{\pm , \circ }_\nu (z)\) and \(\Phi ^{\pm , \circ }_\nu (z)\) have no poles on \(\mathbb {R}\), they have no poles on some open neighborhood of \([-1,1]\). Hence they are \(C^2\) on this interval. Since \(w(0) = \nu \), we see that \(\Phi ^{\pm , \ast }_\nu (0)=0\), giving the claim.
\(\varphi \) is \(C^2\) on \([0,1]\).
Since \(\Phi ^{\pm , \circ }_\nu (z)\) and \(\Phi ^{\pm , \circ }_\nu (z)\) have no poles on \(\mathbb {R}\), they have no poles on some open neighborhood of \([-1,1]\). Hence they are \(C^2\) on this interval. Since \(w(0) = \nu \), we see that \(\Phi ^{\pm , \ast }_\nu (0)=0\), giving the claim.
\(\varphi \) is continuous on \([0,1]\).
By the preceding lemmas it suffices to verify continuity at \(0, -1, 1\). Continuity at \(0\) is clear. For \(t = -1, 1\), by \(\coth \frac{w(t)}{2} = \coth \frac{\nu }{2}\), we see that \(B^{\pm }(w(t)) = \left(\frac{\nu }{2} - \pi i t\right)\left(\coth \frac{\nu }{2} \pm 1\right)\), and so
hence, by Definition 9.6.6, \(\varphi ^{\pm }_{\nu }(t) = 0\). Thus, \(\varphi ^{\pm }_{\nu }\) is continuous at \(-1\) and at \(1\).
Let \(0 {\lt} \nu _0 \leq \nu _1\) and \(c {\gt} - \nu _0/2\pi \), then there exists \(C\) such that for all \(\nu \in [\nu _0, \nu _1]\), \(\Im z \geq c\) one has \(|\Phi ^{\pm ,\circ }_{\nu }(z)| \leq C\).
The function \(\coth w = 1 + \frac{2}{e^{2w}-1}\) is bounded away from the imaginary line \(\Re w = 0\), that is, it is bounded on \(\Re w \geq \kappa \) and \(\Re w \leq -\kappa \) for any \(\kappa {\gt} 0\). The map \(w(z) = \nu - 2\pi i z\) sends the line \(\Im z = -\frac{\nu }{2\pi }\) to the imaginary line, and the region \(\Im z \geq c\) is sent to \(\Re w \geq 2\pi c + \nu \).
Let \(0 {\lt} \nu _0 \leq \nu _1\) and \(c {\lt} - \nu _1/2\pi \), then there exists \(C\) such that for all \(\nu \in [\nu _0, \nu _1]\), \(\Im z \leq c\) one has \(|\Phi ^{\pm ,\circ }_{\nu }(z)| \leq C\).
Similar to previous lemma.
Let \(0 {\lt} \nu _0 \leq \nu _1\) and \(c {\gt} - \nu _0/2\pi \), then there exists \(C\) such that for all \(\nu \in [\nu _0, \nu _1]\), \(\Im z \geq c\) one has \(|\Phi ^{\pm ,\star }_{\nu }(z)| \leq C (|z|+1)\).
The bound on \(\Phi ^{\pm ,\star }_{\nu }\) follows from the bound on \(\Phi ^{\pm ,\circ }_{\nu }\) by \(\Phi ^{\pm ,\star }(z) = \frac{1}{2\pi i}\bigl(w\, \Phi ^{\pm ,\circ }(w) - \nu \, \Phi ^{\pm ,\circ }(\nu )\bigr)\).
Let \(0 {\lt} \nu _0 \leq \nu _1\) and \(c {\lt} - \nu _1/2\pi \), then there exists \(C\) such that for all \(\nu \in [\nu _0, \nu _1]\), \(\Im z \leq c\) one has \(|\Phi ^{\pm ,\star }_{\nu }(z)| \leq C (|z|+1)\).
Similar to previous lemma.
For real \(t\), \(B^+(t)\) is increasing.
For all \(t \neq 0\), by the identities \(2\cosh \frac{t}{2}\sinh \frac{t}{2} = \sinh t\) and \(2\sinh ^2\frac{t}{2} = \cosh t - 1\),
Since \(e^u\) is convex, \(e^u \geq 1 + u\) for all \(u \in \mathbb {R}\). We apply this inequality with \(u = t\) and \(u = -t\) and obtain the conclusion for \(t \neq 0\). Since \(B^{\pm }(t)\) is continuous at \(t = 0\), we are done. .
For real \(t\), \(B^-(t)\) is decreasing.
Similar to previous. .
By the definition of the Fourier transform, and the fact that \(\varphi ^{\pm }_{\nu }\) is supported on \([-1,1]\).
If \(x {\lt} 0\), then
Since \(\Phi ^{\pm ,\circ }_{\nu }(z) \pm \Phi ^{\pm ,\star }_{\nu }(z)\) has no poles in the upper half plane, we can shift contours upwards, as we may: for \(\Im z \to \infty \), \(e(-zx) = e^{-2\pi i z x}\) decays exponentially on \(\Im z\), while, by Lemma 1.3, \(\Phi ^{\pm ,\circ }_{\nu }(z) \pm \Phi ^{\pm ,\star }_{\nu }(z)\) grows at most linearly, and so the contribution of a moving horizontal segment goes to \(0\) as \(\Im z \to \infty \).
For any integer \(m\),
This follows from the \(\pi i\)-periodicity of coth.
For any integer \(m\),
Follows from previous lemma.
If \(x {\lt} 0\), then \(\widehat{\varphi ^{\pm }_{\nu }}(x)\) equals
We have \(\Phi ^{\pm ,\circ }_{\nu }(z) - \Phi ^{\pm ,\star }_{\nu }(z) = -\Phi ^{\pm ,\star }_{\nu }(z+1)\) and \(\Phi ^{\pm ,\circ }_{\nu }(z) + \Phi ^{\pm ,\star }_{\nu }(z) = \Phi ^{\pm ,\star }_{\nu }(z-1)\), and so the formula in the previous lemma simplifies to
If \(x {\gt} 0\), then
We would like to integrate along \(\Re z = 0\), but \(\Phi ^{\pm ,\circ }_{\nu }(z)\) has a pole at \(z = -\frac{i\nu }{2\pi }\); when dealing with this issue, we have to take care not to introduce poles on the lines \(\Re z = -1\) and \(\Re z = 1\) by separating \(\Phi ^{\pm ,\circ }_{\nu }\) and \(\Phi ^{\pm ,\star }_{\nu }\) prematurely. As \(\Im z \to -\infty \), \(e(-zx) = e^{-2\pi i z x}\) decays exponentially on \(\Im z\), while, by Lemma 1.3, \(\Phi ^{\pm ,\circ }_{\nu }(z) \pm \Phi ^{\pm ,\star }_{\nu }(z)\) grows at most linearly.
since the pole is at \(-\frac{i\nu }{2\pi }\), the residue of \(\Phi ^{\pm ,\circ }_{\nu }(z)\) at the pole is \(\frac{i}{2\pi }\), and our path goes clockwise. .
Again by Cauchy’s theorem and decay as \(\Im z \to -\infty \)
Similar to previous.
If \(x {\gt} 0\), then \(\widehat{\varphi ^{\pm }_{\nu }}(x) - e^{-\nu x}\) equals
Let \(\nu {\gt} 0\), \(x {\lt} 0\). Since \(x {\lt} 0\), \(I_{\nu }(x) = 0\), and
This follows from the previous lemma.
Let \(\nu {\gt} 0\), \(x {\gt} 0\). Then
This follows from the previous lemma.
\(\widehat{\varphi ^{\pm }_{\nu }}(x)\) is real.
This follows from the symmetries of \(\varphi ^{\pm }_{\nu }\).
The function \(\varphi _\nu ^\pm \) is integrable.
For \(\nu {\gt} 0\), define \(I_\nu (x) := 1_{[0,\infty )}(x) e^{-\nu x}\).
For all \(x \in \mathbb {R}\),
By Lemmas 9.6.16, 9.6.17, the integrands in Lemmas 9.6.18, 9.6.19 are non-negative. Hence, the bound holds for all \(x \neq 0\). By definition, \(I_\nu \) is right-continuous. Since \(\varphi _\nu ^\pm \in L^1(\mathbb {R})\), \(\widehat{\varphi _\nu ^\pm }\) is continuous on \(\mathbb {R}\). Thus, letting \(x \to 0^+\), we see that the bound holds for \(x = 0\) as well.
The function \((\varphi _\nu ^\pm )'\) is integrable.
The function \(\varphi _\nu ^\pm \) is absolutely continuous.
The function \((\varphi _\nu ^\pm )'\) has finite total variation.
Since \((\varphi _\nu ^\pm )'\) is \(C^1\) on \([-1, 0]\) and on \([0, 1]\), the \(L^1\) norm of \((\varphi _\nu ^\pm )''\) on each of these intervals is finite, and so \((\varphi _\nu ^\pm )'\) has finite total variation on each of them. As \((\varphi _\nu ^\pm )'\) has right and left limits at \(-1\), \(0\) and \(1\), the jumps at those points are finite, and so their contribution to \(\| (\varphi _\nu ^\pm )'\| _{\mathrm{TV}}\) is finite. /
For \(|x| \to \infty \), \(\widehat{\varphi _\nu ^\pm }(x) = O(1/x^2)\).
For \(f\) absolutely continuous with \(f, f' \in L^1(\mathbb {R})\), integration by parts gives us that \(\hat{f}(x) = \widehat{f'}(x)/(2\pi i x)\). If \(f' \in L^1(\mathbb {R})\) with \(\| f'\| _{\mathrm{TV}} {\lt} \infty \), then, again by integration by parts, \(|\widehat{f'}(x)| \leq |f'|_{\mathrm{TV}}/(2\pi x)\). We are done by the preceding lemmas.
We know that \(\varphi _\nu ^\pm \) is continuous and in \(L^1(\mathbb {R})\); by Corollary 9.6.2, \(\widehat{\varphi _\nu ^\pm }\) is in \(L^1(\mathbb {R})\). Hence, Fourier inversion holds everywhere, and in particular for \(t = 0\):
By definition, \(\varphi _\nu ^\pm (0) = \Phi _\nu ^{\pm ,\circ }(0)\), and, by definition, \(\Phi _\nu ^{-,\circ }(0) = \frac{1}{e^\nu - 1}\) and \(\Phi _\nu ^{+,\circ }(0) = \frac{1}{1 - e^{-\nu }}\). Thus,
since \(\int _{-\infty }^{\infty } I_\nu (x)\, dx = 1/\nu \). We are done by Corollary 9.6.1.
See previous.
If \(|\Im z| \leq \frac{\pi }{4}\), then \(|(z \coth z)'| {\lt} 1\).
Since \(z\coth (z)\) is regular at \(0\) and an even function, we see that \(f(z) := (z \coth z)'\) and \(f(z)/z\) are regular at \(0\), and hence analytic on the strip \(|\Im z| \leq \frac{\pi }{2}\). We see from \(f(z) = \coth z - z\operatorname {csch}^2 z\) that \(f(z)\) has at most exponential growth as \(\Re z \to \pm \infty \) within the strip. Hence, by Phragmén–Lindelöf, it is enough to verify the inequalities \(|f(z)/z| \leq 1\) for \(\Im z = \pm \frac{\pi }{2}\) and \(|f(z)| \leq 1\) for \(\Im z = \pm \frac{\pi }{4}\); by complex conjugation, it suffices to check them for \(\Im z = \frac{\pi }{2}\) and \(\Im z = \frac{\pi }{4}\).
By the above, \(f(z) = \frac{(\sinh 2z)/2 - z}{\sinh ^2 z}\). Now, for \(z = x + i\frac{\pi }{4}\) with \(x \in \mathbb {R}\), we have \(\sinh 2z = i\cosh 2x\) and \(\sinh ^2 z = -\frac{1}{2} + \frac{i}{2}\sinh 2x\), and so \(|f(z)|^2 = \frac{(\cosh 2x - \pi /2)^2 + 4x^2}{1 + \sinh ^2 2x}\). By \(1 + \sinh ^2 2x = \cosh ^2 2x\),
Since \(\cosh 2x = 1 + 2\sinh ^2 x \geq 1 + 2x^2\), \(\pi {\gt} \frac{\pi ^2}{4}\) and \(2\pi {\gt} 4\), the numerator here is positive. We conclude that \(|f(z)|^2 {\lt} 1\) for \(z = x + i\frac{\pi }{4}\), as was desired.
For \(z = x + i\frac{\pi }{2}\) with \(x \in \mathbb {R}\), we have \(\coth z = \tanh x\) and \(\operatorname {csch}^2 z = -\operatorname {sech}^2 x\). Then \(|f(z)|^2 = (\tanh x + x\operatorname {sech}^2 x)^2 + \left(\frac{\pi }{2}\operatorname {sech}^2 x\right)^2\). Since \(\operatorname {sech}^2 x - 1 = -\tanh ^2 x\), this is equal to
Since \(|z|^2 \geq \frac{\pi ^2}{4} {\gt} 2\), it suffices to show that \(2x\operatorname {csch} x - 2\operatorname {sech} x - \cosh x \leq 0\) for all \(x \in \mathbb {R}\); by parity, it is enough to check all \(x \geq 0\). The statement is then equivalent to \(g(x) = 2x - 2\tanh x - \sinh x \cosh x \leq 0\), since \(\sinh x \geq 0\). That follows from \(g'(x) = 2\tanh ^2 x - \cosh ^2 x - \sinh ^2 x = -2\sinh ^2 x \tanh ^2 x - 1 \leq 0\) (by \(1 - \cosh ^2 x = -\sinh ^2 x\)) and \(g(0) = 0\).
If \(|\Im z| \leq \frac{\pi }{2}\), then \(|(z \coth z)'| \leq |z|\).
See previous.
9.6.3 Contour shifting
This section formalises [ 9 , Section 5 ] . We collect here the notation and the standing hypotheses shared by Lemma 9.6.25 (contour shifting) and its sub-lemmas.
Ladder parameters. We fix:
a half-height \(T {\gt} 0\) and a contour height \(\delta \in (0, T/4)\). (We write \(\delta \) for the paper’s contour height \(\varepsilon \), since \(\varepsilon \) already denotes the \(\pm 1\) sign in the extremal-approximant notation above.)
truncation abscissae \(\sigma \colon \mathbb {N} \to \mathbb {R}\) with \(\sigma _0 = 1\), \(\sigma _n \leq 1\), and \(\sigma _n \to -\infty \); these are the leftward shift levels in the proof.
Regions and contours. Write \(s = \Re s + i\, \Im s\). We use:
the rectangle \(R = \{ s : \Re s \leq 1,\ |\Im s| \leq T \} \) and its boundary \(\partial R\);
the ladder \(L = \bigcup _{n \geq 1} \{ \sigma _n + i t : |t| \leq T \} \) (the columns above \(\sigma _n\) for \(n \geq 1\); the \(\sigma _0 = 1\) column is part of \(\partial R\));
the (simplified) admissible contour \(C\): up from \(1\) to \(1 + i\delta \), then leftward along \(\Im s = \delta \) to \(-\infty \), with conjugate \(\overline{C}\);
\(R^+ = \{ \Re s \leq 1,\ \delta \leq \Im s \leq T \} \) (the part of \(R\) above \(C\)), its conjugate \(\overline{R^+} = \{ \Re s \leq 1,\ -T \leq \Im s \leq -\delta \} \) (below \(\overline{C}\)), and \(R_C = \{ \Re s \leq 1,\ |\Im s| \leq \delta \} \) (between \(C\) and \(\overline{C}\)). Thus \(R = R^+ \sqcup R_C \sqcup \overline{R^+}\), so \(R \setminus R_C = R^+ \sqcup \overline{R^+}\);
the horizontal rays \(C_\infty \): \(\{ \Im s = \pm T,\ \Re s \leq 1 \} \) (the top and bottom of \(R\) continued to \(-\infty \)).
The function \(G\). We are given a decomposition \(G(s) = G^\circ (s) + \mathrm{sgn}(\Im s)\, G^\star (s)\) in which \(G^\circ \) and \(G^\star \) are meromorphic on \(R\) and \(G^\star \) is conjugation-antisymmetric, \(G^\star (\bar s) = -\overline{G^\star (s)}\) (so for real \(x\) the integrand \(s \mapsto G^\star (s) x^s\) is too; this is what lets the integrals over \(C\) and \(\overline{C}\) combine into a single \(\frac{1}{\pi } \Im \int _C G^\star x^s\) term). We fix reals \(1 \leq x_0 {\lt} x\) and assume \(G(s) x_0^s\) is bounded with no poles on \(\partial R\), and that both \(G^\circ (s) x_0^s\) and \(G^\star (s) x_0^s\) are bounded with no poles on the ladder \(L\) and on the contour \(C\).
Truncated contours (used in the proof). At truncation level \(n\):
\(C_n^+\): from \(1\), follow \(C\) leftward to \(\sigma _n + i\delta \), then up to \(\sigma _n + iT\), then right to \(1 + iT\); \(C_n^-\) is the conjugate, traversed backwards;
\(C_{n,1}^\pm \): the contour \(C_n^\pm \) with its horizontal \(\Im s = \pm T\) segment removed;
the \(\sigma _n\) column \(\{ \sigma _n + it : |t| \leq T \} \).
Each contour integral carries the orientation just described; the prefactors \(\frac{1}{2\pi i}\) and \(\frac{1}{\pi } \Im \) are written explicitly at each occurrence rather than baked into the contours.
Residues (temporary scaffold). Mathlib has no general residue theorem yet, so \(\mathrm{Res}_{s=\rho }\) denotes the simple-pole residue \(\lim _{s \to \rho } (s - \rho ) f(s)\), and a sum \(\sum _{\rho \in S} \mathrm{Res}_{s=\rho }\) is the sum of these over the poles of the integrand in \(S\). Over the bounded off-axis region \(R \setminus R_C\) this is a finite sum (we assume finitely many poles there). Over \(R_C\), which may contain infinitely many poles on the real axis (e.g. the trivial zeros of \(\zeta \)), it is taken in the improper sense \(\lim _{n \to \infty } \sum _{\rho \in R_C,\ \Re \rho {\gt} \sigma _n} \mathrm{Res}_{s=\rho }\). We also assume throughout that every pole in \(R\) is at most simple. These last conventions are scaffolding to be removed once Mathlib gains a general (higher-order) residue theorem.
For each \(n\), shifting the upper half \(1 \to 1 + iT\) of the central line leftwards to the truncated contour \(C_n^+\) picks up the residues of \(G\) in \(R^+\) to the right of \(\sigma _n\):
The residue theorem on the region of \(R^+\) between \([1, 1+iT]\) and \(C_n^+\).
For each \(n\), shifting the lower half \(1 - iT \to 1\) of the central line leftwards to the truncated contour \(C_n^-\) picks up the residues of \(G\) in \(\overline{R^+}\) to the right of \(\sigma _n\):
The residue theorem on the region of \(\overline{R^+}\) between \([1-iT, 1]\) and \(C_n^-\).
Shifting the \(C_{n,1}^{\pm }\) parts of the truncated contours onto the line \(\Re s = \sigma _n\) replaces them by the \(\sigma _n\) column, picking up the residues of \(G^\circ \) in \(R_C\) to the right of \(\sigma _n\):
The residue theorem on the region of \(R_C\) between \(C_{n,1}^+ \cup C_{n,1}^-\) and the \(\sigma _n\) column.
Since \(C_{n,1}^-\) is the conjugate of \(C_{n,1}^+\) traversed backwards and \(G^\star (\bar s) = -\overline{G^\star (s)}\), the two \(G^\star \) contour integrals combine into a single imaginary part:
For the conjugation-antisymmetric integrand \(G^\star x^s\), \(\int _{C_{n,1}^-} = \overline{\int _{C_{n,1}^+}}\), and \(z - \bar z = 2i\, \Im z\).
As \(n \to \infty \) (so \(\sigma _n \to -\infty \)), the top segment of \(C_n^+\) together with the bottom segment of \(C_n^-\) converge to the contour \(C_\infty \):
As \(\sigma _n \to -\infty \) the truncated horizontal segments exhaust the rays of \(C_\infty \); uses boundedness of \(G x_0^s\) on \(\partial R\) and \(x {\gt} x_0\).
As \(n \to \infty \) (so \(\sigma _n \to -\infty \)), the integral of \(G^\circ x^s\) over the \(\sigma _n\) column tends to \(0\):
The integrand is \(O((x/x_0)^{\sigma _n})\) via boundedness of \(G^\circ x_0^s\) on \(L\), and \((x/x_0)^{\sigma _n} \to 0\) since \(x {\gt} x_0 \geq 1\) and \(\sigma _n \to -\infty \).
If \(f\) is meromorphic on a region \(S\) and has only finitely many poles there, then the truncated residue sums over \(S \cap \{ \Re s {\gt} \sigma _n\} \) converge, as \(n \to \infty \), to the full sum over \(S\). (Indeed they are eventually equal to it, once \(\sigma _n\) has dropped below the real part of every pole.)
Since \(\sigma _n \to -\infty \) and there are finitely many poles in \(S\), for all large \(n\) the set \(\{ \Re s {\gt} \sigma _n\} \) contains every pole of \(f\) in \(S\); meromorphicity on \(S\) makes the residue vanish at non-poles, so the truncated sum is then constant and equals the full residue sum over \(S\).
As \(n \to \infty \) (so \(\sigma _n \to -\infty \)), the integral of \(G^\star x^s\) over \(C_{n,1}^+\) converges to its integral over the full contour \(C\):
\(C_{n,1}^+\) differs from \(C\) (truncated at height \(\delta \)) only in its horizontal segment \(1 + i\delta \to \sigma _n + i\delta \), which exhausts the ray \(1 + i\delta \to -\infty + i\delta \), and its vertical segment \(\sigma _n + i\delta \to \sigma _n + iT\), which vanishes — both as in 9.6.19, 9.6.20, here at height \(\delta \), using boundedness of \(G^\star x_0^s\) on \(L\) and on \(C\).
Let \(G = G^\circ + \mathrm{sgn}(\Im s)\, G^\star \) with \(G^\circ , G^\star \) meromorphic on \(R = (-\infty ,1] + i[-T,T]\), and suppose \(G^\star (\bar s) = -\overline{G^\star (s)}\). Suppose for some \(x_0 \geq 1\) that \(G(s) x_0^s\) is bounded with no poles on \(\partial R\), and both \(G^\circ (s) x_0^s\) and \(G^\star (s) x_0^s\) are bounded with no poles on the ladder \(L\) and the contour \(C\). Then for any \(x {\gt} x_0\),
where the first sum runs over the (finitely many — see the hypotheses) poles of \(G\) in the bounded off-axis strip \(R \setminus R_C\), while the second is the improper residue sum of \(G^\circ \) over \(R_C\), i.e. the limit of the truncations \(R_C \cap \{ \Re s {\gt} \sigma _n\} \) as \(n \to \infty \). The improper sum allows infinitely many poles on the real axis (e.g. the trivial zeros of \(\zeta \)), where an ordinary sum need not converge.
Temporary scaffold: we additionally assume every pole of \(G\) (resp. \(G^\circ \)) in \(R\) is at most simple (\(\mathrm{HasSimplePolesOn}\)). The formalised residue and the current Mathlib residue-theorem API are only valid for simple poles; this hypothesis holds in the intended applications and is to be dropped once higher-order residue support lands.
Assemble from the sub-lemmas. Split the central line into its upper half \([1,1+iT]\) and lower half \([1-iT,1]\), and apply Lemmas 9.6.15 and 9.6.16 to rewrite each as the truncated contour \(C_n^+\) (resp. \(C_n^-\)) plus the residues of \(G\) over \(R^+ \cap \{ \Re s {\gt} \sigma _n\} \) (resp. \(\overline{R^+} \cap \{ \Re s {\gt} \sigma _n\} \)). Split each \(C_n^{\pm }\) into its horizontal \(\Im s = \pm T\) segment and the remainder \(C_{n,1}^{\pm }\). On \(C_{n,1}^{\pm }\) substitute \(G = G^\circ + \mathrm{sgn}(\Im s)\, G^\star \): by 9.6.17 the \(G^\circ \) part becomes the \(\sigma _n\) column plus the residues of \(G^\circ \) over \(R_C \cap \{ \Re s {\gt} \sigma _n\} \), and by 9.6.18 the \(G^\star \) part combines into \(2i\, \Im \int _{C_{n,1}^+} G^\star x^s\). Now let \(n \to \infty \): the \(\Im s = \pm T\) segments converge to \(C_\infty \) (9.6.19); the \(\sigma _n\) column vanishes (9.6.20); \(C_{n,1}^+ \to C\) (9.6.22), so \(\Im \int _{C_{n,1}^+} G^\star x^s \to \Im \int _C G^\star x^s\); the off-axis truncated sums converge to the full (finite) residue sums over \(R^+ \sqcup \overline{R^+} = R \setminus R_C\) (9.6.21), while the \(R_C\) truncated sum converges to the improper residue sum by definition. Collecting terms, and using \(\frac{1}{2\pi i} \cdot 2i = \frac{1}{\pi }\), yields the claim.
Under the hypotheses of 9.6.6, with \(G\), \(G^\circ \), \(G^\star \), \(z(s)\) as there, the decomposition \(G = G^\circ + \mathrm{sgn}(\Im s)\, G^\star \) holds (as \(\mathrm{sgn}(\Re z(s)) = \mathrm{sgn}(\Im s)\), since \(\Re z(s) = \Im s / T\) and \(T {\gt} 0\)), \(G^\star \) is conjugation-antisymmetric, and the boundedness hypotheses of Lemma 9.6.25 hold; hence Lemma 9.6.25 gives
Apply Lemma 9.6.25. The \(G^\star \) reflection is the conjugation symmetry of \(\Phi ^\star \) together with \(F(\bar s) = \overline{F(s)}\); boundedness follows from \(\Phi ^\circ \) bounded and \(\Phi ^\star = O(|z|)\) (CH2 Lemma 4.3).
On the rays of \(C_\infty \), \(z(r \pm iT) = \pm 1 + i\, \frac{1-r}{T}\), so \(|\Phi ^\varepsilon _\lambda (z(s))| \leq \frac{1-r}{T}\) (CH2 Lemma 4.3); substituting \(t = 1 - r\),
\(|\Phi ^\varepsilon _\lambda (\pm 1 + ir')| \leq |r'|\) (CH2 Lemma 4.3), \(|x^s| = x^{\Re s}\).
Since \(G^\star = \mathrm{sgn}(\lambda )\, \Phi ^\star _{|\lambda |, \varepsilon }(\mathrm{sgn}(\lambda ) z(\cdot )) F\) and \(|\Im w| \leq |w|\),
‘intC‘ is linear, \(|\mathrm{sgn}(\lambda )| = 1\), and \(|\Im w| \leq |w|\).
This specialises Lemma 9.6.25 to the weight \(\Phi ^\varepsilon _\lambda \) built from the Graham–Vaaler approximants. The notation differs from [ 9 ] : the paper’s sign \(\pm \) is here the parameter \(\varepsilon \in \{ +1, -1\} \) carried by \(\Phi ^\circ \), \(\Phi ^\star \) (the formalisation’s Phi_circ, Phi_star), and the paper’s contour height \(\varepsilon \) is our \(\delta \) (so \(C\) is the LadderParams contour at height \(\delta \)).
Let \(F \colon \mathbb {C} \to \mathbb {C}\) be meromorphic on \(R = (-\infty , 1] + i[-T, T]\) with \(F(\bar s) = \overline{F(s)}\), and suppose for some \(x_0 \geq 1\) that \(F(s) x_0^s\) is bounded with no poles on \(\partial R \cup C \cup L\). Fix \(\lambda \neq 0\) and \(\varepsilon \in \{ +1, -1\} \), write \(z(s) = \frac{s - 1}{iT}\), and set
This is the \(G = G^\circ + \mathrm{sgn}(\Im s)\, G^\star \) of Lemma 9.6.25, with \(G(s) = \Phi ^\varepsilon _\lambda (z(s)) F(s)\), \(G^\circ (s) = \Phi ^\circ _{|\lambda |, \varepsilon }(\mathrm{sgn}(\lambda ) z(s)) F(s)\), and \(G^\star (s) = \mathrm{sgn}(\lambda )\, \Phi ^\star _{|\lambda |, \varepsilon }(\mathrm{sgn}(\lambda ) z(s)) F(s)\). Then, for any \(x {\gt} x_0\),
where the second sum is the improper residue sum (a limit of truncations \(R_C \cap \{ \Re s {\gt} \sigma _n\} \), allowing the infinitely many real-axis poles) of \(\Phi ^\circ _{|\lambda |, \varepsilon }(\mathrm{sgn}(\lambda ) z(s)) F(s)\) over \(R_C\), whose poles include that of \(\Phi ^\circ \) at \(1 + \frac{\lambda T}{2\pi }\) when \(\lambda {\lt} 0\), and
Here \(O^*(E)\) is rendered as \(\| \cdot \| \leq E\). The first part of \(E\) bounds the \(C_\infty \) integral of Lemma 9.6.25 (via \(|\Phi ^\varepsilon _\lambda (\pm 1 + ir)| \leq |r|\) on the lines \(\Re s = \pm 1\)), and the second is its \(\frac{1}{\pi } \Im \int _C G^\star \) term.
Temporary scaffold: as in Lemma 9.6.25, we assume every pole in \(R\) is at most simple (\(\mathrm{HasSimplePolesOn}\)), since the formalised residue is only valid for simple poles; this is to be removed once Mathlib gains higher-order residue support.
9.6.4 The main theorem
TODO: incorporate material from [ 9 , Section 6 ] .
9.6.5 Applications to psi
TODO: incorporate material from [ 9 , Section 7 ] onwards.
Assume the Riemann hypothesis holds up to height \(T \geq 10^7\). For \(x {\gt} \max (T,10^9)\),
TBD.
Assume the Riemann hypothesis holds up to height \(T \geq 10^7\). For \(x {\gt} \max (T,10^9)\),
where \(\gamma = 0.577215...\) is Euler’s constant.
TBD.
For \(x \geq 1\),
where \(\psi (x)\) is the Chebyshev function.
TBD.
For \(x \geq 1\),
TBD.
9.7 Summary of results
In this section we list some papers that we plan to incorporate into this section in the future, and list some results that have not yet been moved into dedicated paper sections.
References to add:
None yet.