REVIEW
The Goldbach exceptional set: an exponent 7/12 and conditional refinement
Number Theory · Submitted 11 Oct 2026 · 13 references
Pith's verdict: Conditional 7/12 Goldbach bound that is honestly conditional—clear dependencies, novel combination, but rests on two unverified preprints.
T0 · AI review
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Referee report
The paper
The paper claims
In the presence of a common zero-free half-plane for Dirichlet L-functions, the Goldbach exceptional set is bounded by X^{7/12+ε}, and under stronger zero hypotheses the exponent can be pushed strictly below that value.
The reading
What carries the argument
For Theorem~1, the main tools are Pintz's explicit formula [8] for the major arcs and the Maynard–Pandey–Radziwiłł exponential‑sum bound [3] which gives a $19/24$ exponent on $X$ in the minor‑arc supremum, leading to $7/12$ after Bessel's inequality. For Theorem~3, the central object is Lemma~4, an asymptotic expansion for the smoothed exponential sum $F_X(\alpha)$ near rational $a/q$. It uses character expansion, contour integration, and the fixed‑modulus zero‑density estimate $N_q(\sigma,U) \ll (qU)^{3(1-\sigma)/(2-\sigma)}\log^9(qU)$ (from [11] or [4]) to bound the contribution of zeros. The resulting uniform approximation yields a bound $X^{a(\theta)+\eta}$ for the $L^\infty$ deviation, which through $L^2$ comparison gives the exceptional‑set exponent $g(\theta)=2a(\theta)-1$.
Extended reading notes
Core claim
The central discovery is that the exponent in the Goldbach exceptional set can be conditionally reduced to $7/12$ (Theorem~1) and, under the uniform zero bound $H_\theta$ with $\theta\le2/3$, to the even smaller exponent $g(\theta)=\theta(5-4\theta)/(2(2-\theta))$ (Theorem~3). The proof of Theorem~1 combines Pintz's explicit major‑arc formula with the exponential‑sum estimate of Maynard, Pandey, and Radziwiłł to handle the minor arcs, while Theorem~3 uses a classical fixed‑modulus zero‑density estimate in place of the new exponential‑sum bound. The key insight is that once the major arcs contribute a positive main term (guaranteed by the zero‑free hypothesis), the minor‑arc estimate becomes the limiting factor, and the choice of zero‑density estimate determines the final exponent.
Load-bearing premise
Both theorems assume unproven properties of Dirichlet $L$-function zeros: Theorem~1 requires a common zero‑free half‑plane (supplied by an external, non‑trivial theorem), and Theorem~3 requires that all nontrivial zeros have real part at most $\theta$ for some fixed $\theta\le 2/3$.
Editorial extensions
If this is right
- If the common zero‑free half‑plane assumption holds (e.g. as claimed by an external theorem), the Goldbach exceptional set has size at most $X^{7/12+\varepsilon}$, improving on the previous best exponent $0.684$ from unpublished numerical work.
- For any fixed $\theta<2/3$ for which $H_\theta$ holds, the exponent drops below $7/12$; for example $H_{5/8}$ gives $E(X)\ll X^{25/44+\varepsilon}$, a gap of $1/66$.
- The proof of Theorem~3 is independent of the new exponential‑sum theorem and relies only on classical zero‑density estimates, showing that the conditional improvement is robust to the choice of minor‑arc technology.
- The method makes explicit how the location of Dirichlet zeros quantitatively controls the number of even numbers that fail to be sums of two primes.
Reading between the lines
- The entire edifice of Theorem~1 and its corollary rests on an external, non‑trivial zero‑free theorem that has not yet appeared in peer‑reviewed literature. Until that result is independently verified, the $7/12$ exponent remains a conditional implication, not a proven bound.
- Theorem~3 shows that if one is willing to assume $H_\theta$ with $\theta$ as high as $2/3$, the exponent $7/12$ is already the worst case; any improvement on the zero hypothesis immediately pays off in the exceptional set. This suggests that further progress on the Goldbach problem may come from better zero‑free regions for Dirichlet $L$-functions.
- The paper explicitly notes that the Guth–Maynard zero‑density estimate does not sharpen the argument because its range of applicability ($\sigma>7/10$) lies above the $\theta\le2/3$ considered here. A fixed‑modulus analogue of that estimate would not help either, as the exponent $D(\sigma)$ in (4.1) is already optimal for $\sigma\le2/3$ among known estimates.
Original abstract
Let \(E(X)\) count the even integers between \(4\) and \(X\) that are not sums of two primes. We combine Pintz's explicit formula for the major arcs with the exponential-sum estimate of Maynard, Pandey, and Radziwi{\l}{\l} to prove \(E(X)\ll_\varepsilon X^{7/12+\varepsilon}\) whenever all Dirichlet \(L\)-functions have a common fixed zero-free half-plane \(\Rea s>\theta_0\), with \(\theta_0<1\). The uniform \(7/8\) theorem reported in the OpenAI mathematics release supplies this input. Under the stronger hypothesis that every nontrivial Dirichlet zero has real part at most \(\theta\), where \(1/2\leq\theta\leq2/3\), we prove \[ E(X)\ll_{\theta,\varepsilon}X^{g(\theta)+\varepsilon}, \qquad g(\theta)=\frac{\theta(5-4\theta)}{2(2-\theta)}. \] Thus every fixed \(\theta<2/3\) gives an exponent strictly below \(7/12\). The latter argument uses a classical fixed-modulus zero-density estimate and is independent of the new exponential-sum theorem.
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
Let \(E(X)\) count the even integers between \(4\) and \(X\) that are not sums of two primes. We combine Pintz's explicit formula for the major arcs with the exponential-sum estimate of Maynard, Pandey, and Radziwi{\l}{\l} to prove \(E(X)\ll_\varepsilon X^{7/12+\varepsilon}\) whenever all Dirichlet \(L\)-functions have a common fixed zero-free half-plane \(\Rea s>\theta_0\), with \(\theta_0<1\). The uniform \(7/8\) theorem reported in the OpenAI mathematics release supplies this input. Under the stronger hypothesis that every nontrivial Dirichlet zero has real part at most \(\theta\), where \(1/2\leq\theta\leq2/3\), we prove \[ E(X)\ll_{\theta,\varepsilon}X^{g(\theta)+\varepsilon}, \qquad g(\theta)=\frac{\theta(5-4\theta)}{2(2-\theta)}. \] Thus every fixed \(\theta<2/3\) gives an exponent strictly below \(7/12\). The latter argument uses a classical fixed-modulus zero-density estimate and is independent of the new exponential-sum theorem.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | Let \(E(X)\) count the even integers between \(4\) and \(X\) that are not sums of two primes. | background 1.00 | 0.18 | 0.02 | asserted 0.64 |
| s1 | We combine Pintz's explicit formula for the major arcs with the exponential-sum estimate of Maynard, Pandey, and Radziwi{\l}{\l} to prove \(E(X)\ll_\varepsilon X^{7/12+\varepsilon}\) whenever all Dirichlet \(L\)-functions have a common fixed zero-free half-plane \(\Rea s>\theta_0\), with \(\theta_0<1\). | result 0.71 | 0.92 | 0.70 | asserted 1.00 |
| s2 | The uniform \(7/8\) theorem reported in the OpenAI mathematics release supplies this input. | method 0.49 | 0.05 | 0.04 | asserted 1.00 |
| s3 | Under the stronger hypothesis that every nontrivial Dirichlet zero has real part at most \(\theta\), where \(1/2\leq\theta\leq2/3\), we prove \[ E(X)\ll_{\theta,\varepsilon}X^{g(\theta)+\varepsilon}, \qquad g(\theta)=\frac{\theta(5-4\theta)}{2(2-\theta)}. | result 0.98 | 0.92 | 0.31 | asserted 1.00 |
| s4 | \] Thus every fixed \(\theta<2/3\) gives an exponent strictly below \(7/12\). | interpretation 0.91 | 0.78 | 0.18 | asserted 1.00 |
| s5 | The latter argument uses a classical fixed-modulus zero-density estimate and is independent of the new exponential-sum theorem. | method 0.79 | 0.60 | 0.03 | asserted 1.00 |
What was examined, and what was not
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References
Discussion
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