REVIEW
Improved zero-free half-planes for the quasi-Riemann hypothesis
Number Theory · Submitted 8 Oct 2026
Pith's verdict: A careful parameter re-optimization that shaves 7/8 by 4e-5, with exact algebraic control and honest limitations—but every deep input still rides on an unpublished preprint.
T0 · AI review
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Referee report
The paper
The paper claims
Every finite-order Hecke $L$-function over $\mathbb{Q}(\sqrt{-3})$, and every Dirichlet $L$-function including $\zeta$, is zero-free beyond real part $0.874957$, a slight sharpening of $7/8$ by balancing two length parameters in the…
The reading
What carries the argument
The load-bearing object is the modified cubic-$\theta$ average $J_\eta(Z)$: the reflection principle bounds it directly with exponent $l_x/2 + b/12$, while Poisson summation isolates the principal Mellin integral with exponent $C_b(s) = s - (4 + b)/6$, and matching the two exponents at the boundary $B(\ell) = 11/12 - \ell/4$ determines the zero-free line. Two length scales enter, the element-scale exponents $l_x, l_y$ with difference $b$, and the total logarithmic length $\ell$ of selected auxiliary primes; the competition between lengthening $\ell$ and controlling nonprincipal terms is encoded in the relative exponent $E(b, \ell; \delta, x)$, with $\delta$ the zero-class parameter and $x$ the normalized prime-sum amplitude, at the fixed moment value $\kappa = 3/4$ that the parent bound $\beta^* \le 7/8$ makes legal. The rational part verifies $E \le -19/320000$ by an exact calculation in the Bernstein basis polynomials (nonnegative partition-of-unity polynomials) on a rectangle partition. The algebraic part pivots on the character-count exponent $R^*(\delta, 1/2) = (185 - 288\delta + 96\delta^2)/(185 - 138\delta)$: the class $R^* = 2/3$ forces $\delta_c$, then $\ell_{\mathrm{new}}$ and $b_{\mathrm{new}}$, and the endpoint inequality is settled by the exact identity $4A(y)Q = (2A(y)\delta + D(y))^2 + y(d_1 + d_2 y + d_3 y^2 + d_4 y^3) \ge 0$, with equality only at $(\delta_c, 1/2)$. The optimality statement Proposition 25.1 combines the three affine constraints $B \ge L_0$, $B \ge L_K$, $B \ge H_c$ with positive weights that sum to one and cancel the free lengths, leaving $B \ge B_{\mathrm{new}}$ for every admissible choice.
Extended reading notes
Core claim
The central claim is Theorem 21.1: the family supremum $\beta^*$ over real parts of nontrivial zeros of all primitive finite-order Hecke $L$-functions over $F = \mathbb{Q}(\sqrt{-3})$ satisfies $\beta^* \le B_{\mathrm{new}}$, and consequently every finite-order Hecke $L$-function over $F$, every Dirichlet $L$-function, and $\zeta$ itself is zero-free on $\mathrm{Re}\, s > B_{\mathrm{new}}$, with principal poles at $s = 1$ allowed. Numerically $7/8 - B_{\mathrm{new}} = 4.293 \times 10^{-5}$, but the improvement is structural rather than numerical: the parent $7/8$ argument fixed the parameters at $b = 1/8$, $\ell = 1/6$, while the balanced comparison boundary $B(\ell) = 11/12 - \ell/4$ shows that increasing $\ell$ lowers the boundary, subject to the nonprincipal error exponent $E(b, \ell; \delta, x)$. The new parameters are forced by the critical zero class where the character-count exponent $R^* = 2/3$ cannot be improved by changing $b$: $\delta_c = (49 - \sqrt{921})/48$ is the root of $288\delta^2 - 588\delta + 185 = 0$, $\ell_{\mathrm{new}} = (33 + 8\sqrt{921})/1653$ solves $E = 0$, and $b_{\mathrm{new}} = -4/29 + 230\sqrt{921}/26709$ solves stationarity in $\delta$; the $\sqrt{921}$ is the discriminant of that quadratic, not a free choice. At those parameters the endpoint inequality is an exact quadratic identity with equality only at the critical pair, and Proposition 25.1 proves that under the three explicit affine constraints of the same estimate system every admissible boundary must satisfy $B \ge B_{\mathrm{new}}$. The intermediate rational bound $B_r = 34999/40000$, obtained by moving $\ell$ to $1/6 + 1/10000$ with $b$ fixed, is verified by an exact sign calculation in the Bernstein basis, and the paper reports machine-checked formalizations of both bounds.
Load-bearing premise
The argument leans on the unpublished preprint [1] for every imported moment and error estimate, and those estimates — the unweighted fourth moment at $\kappa = 3/4$, the reflected $\theta$ mean-square, the joint local error, and the parent bound $\beta^* \le 7/8$ — are asserted, not re-derived, at the shifted parameters $b_{\mathrm{new}}, \ell_{\mathrm{new}}$; if any one of them fails there, the endpoint inequality $E \le 0$ does not yield the theorem.
Editorial extensions
If this is right
- Every finite-order Hecke L-function over Q(√−3) and every Dirichlet L-function, including ζ, is zero-free for Re s > B_new ≈ 0.874957, with principal poles at s = 1 allowed; the gap does not narrow with conductor or height.
- Under the three explicit affine constraints of the estimate system, Proposition 25.1 makes B_new the exact endpoint: every admissible choice of free lengths gives B ≥ B_new, with equality at the new lengths; the paper labels broader optimality across the full system an expectation rather than a proved statement.
- Fixing the moment parameter at κ = 3/4, which the parent bound β* ≤ 7/8 makes legal, removes the loss carried by the original varying-moment argument, and the strict comparison margins close in a Mellin-continuation contradiction on the new line.
- The paper notes that letting κ range outside [3/4, 1] could shave about 4.48 × 10⁻⁸ more off B_new, an option left to future work.
Reading between the lines
- The balancing recipe is general: applied to the analogue of the critical class R* = 2/3 in another quadratic base field, or to a different metaplectic theta ladder, the same two-parameter optimization should produce a distinct algebraic endpoint of the same type.
- The single most exposed step is the assertion that the moment and error estimates imported from [1] hold at the shifted parameters; a direct numerical check of the unweighted fourth moment at κ = 3/4 at the new scales would test exactly that.
- The tiny size of the gain suggests the practical ceiling of the method lies in the moment and reflected mean-square inputs rather than in the exponent balancing; improving those inputs uniformly would convert immediately into a new boundary via the same balance equations.
Original abstract
Recently, a uniform $\frac{7}{8}$ zero-free half-plane for finite-order Hecke $L$-functions over $\mathbb Q(\sqrt{-3})$ and its transfer to Dirichlet $L$-functions was given by OpenAI in [Ope26a]. In its proof, there are several parameters $b=\frac{1}{8}, \ell=\frac{1}{6}$, and $\kappa$. In this paper, via varying $b$, $\ell$, and $\kappa$, following the same strategy, we slightly improve the bound $\frac{7}{8}=0.875$ to \[ B_{\mathrm{new}}=\frac{18\xi_{\mathrm{new}}+7}{18\xi_{\mathrm{new}}+9} =0.874957019420098946\ldots, \] where $\xi_{\mathrm{new}}$ is the unique root in $(0.38858,0.38859)$ of $1188\xi^3-2160\xi^2+171\xi+190=0$. Explicitly, with $\arccos\in[0,\pi]$, \[ \xi_{\mathrm{new}}=\frac{20}{33}+\frac{\sqrt{1391}}{33} \cos\!\left(\frac13\arccos\frac{28470}{1391^{3/2}} -\frac{2\pi}{3}\right). \] The limiting parameters are \[ \begin{gathered} b_{\mathrm{new}}=\frac{8(3\xi_{\mathrm{new}}-1)(12\xi_{\mathrm{new}}^2-40\xi_{\mathrm{new}}+15)} {9(2\xi_{\mathrm{new}}+1)(24\xi_{\mathrm{new}}^2-20\xi_{\mathrm{new}}+5)}, \ell_{\mathrm{new}}=\frac{5-6\xi_{\mathrm{new}}}{9+18\xi_{\mathrm{new}}},\qquad \kappa_{\mathrm{new}}=\frac{18\xi_{\mathrm{new}}+5}{18\xi_{\mathrm{new}}+9} =2B_{\mathrm{new}}-1. \end{gathered} \] We also prove its optimality within the explicitly specified exponent comparison system. This result has been formalized by Lean [Liu26].
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
Recently, a uniform $\frac{7}{8}$ zero-free half-plane for finite-order Hecke $L$-functions over $\mathbb Q(\sqrt{-3})$ and its transfer to Dirichlet $L$-functions was given by OpenAI in [1]. In its proof, there are two chosen parameters $b=\frac{1}{8}, \ell=\frac{1}{6}$. In this note, via varying $b$ and $\ell$, following the same strategy, we slightly improve the bound $\frac{7}{8}=0.875$ to be $$B_{\mathrm r}=\frac{34999}{40000}=0.874975, (\text{when }b_{\mathrm r}=\frac{1}{8}, \ell_{\mathrm r}=\frac{1}{6} + \frac{1}{10000});$$ and \[ \begin{gathered} B_{\mathrm{new}}=\frac{1507-2\sqrt{921}}{1653} =0.874957069799\ldots, (\text{when }b_{\mathrm{new}}=-\frac{4}{29}+\frac{230\sqrt{921}}{26709}, \ell_{\mathrm{new}}=\frac{33+8\sqrt{921}}{1653}). \end{gathered} \] This result has been formalized by Lean ([15]).
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | Recently, a uniform $\frac{7}{8}$ zero-free half-plane for finite-order Hecke $L$-functions over $\mathbb Q(\sqrt{-3})$ and its transfer to Dirichlet $L$-functions was given by OpenAI in [1]. | background 1.00 | 0.03 | 0.06 | asserted 1.00 |
| s1 | In its proof, there are two chosen parameters $b=\frac{1}{8}, \ell=\frac{1}{6}$. | background 0.88 | 0.09 | 0.02 | asserted 1.00 |
| s2 | In this note, via varying $b$ and $\ell$, following the same strategy, we slightly improve the bound $\frac{7}{8}=0.875$ to be $$B_{\mathrm r}=\frac{34999}{40000}=0.874975, (\text{when }b_{\mathrm r}=\frac{1}{8}, \ell_{\mathrm r}=\frac{1}{6} + \frac{1}{10000});$$ and \[ \begin{gathered} B_{\mathrm{new}}=\frac{1507-2\sqrt{921}}{1653} =0.874957069799\ldots, (\text{when }b_{\mathrm{new}}=-\frac{4}{29}+\frac{230\sqrt{921}}{26709}, \ell_{\mathrm{new}}=\frac{33+8\sqrt{921}}{1653}). | result 0.82 | 0.94 | 0.93 | asserted 1.00 |
| s3 | \end{gathered} \] This result has been formalized by Lean ([15]). | result 0.36 | 0.32 | 0.06 | asserted 1.00 |
What was examined, and what was not
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References
Discussion
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