files / problems / riemann-hypothesis / compute / q2 / ANALYTIC_REVIEW.md

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Analytic review of the pinned candidate

This review checks the mathematical transfer separately from its numerical obligations. CLAIM.md gives the current certification status. The candidate and its new lemmas belong to Jude Gomila; this folder is a reproduction and audit with a new independent finite algorithm.

The source is commit a74738deb6d5e0f76887cb36901da08b68dca705 of the candidate repository. The published inputs are Polymath 15, Theorems 1.2 and 1.3, arXiv:1904.12438v2, and Platt–Trudgian, Theorem 1 and Corollary 2, arXiv:2004.09765v1. Both PDFs were fetched and their statements read again for this campaign.

The theorem's domains

For the exact parameters in CLAIM.md, the criterion needs the following:

  1. No zeta zero with real part at least (1+y0)/2(1+y_0)/2 and ordinate from zero through X/2X/2.
  2. At time t0t_0, no zero of the deformed function to the right of X+1−y02X+\sqrt{1-y_0^2} and between heights y0y_0 and 1−2t0\sqrt{1-2t_0}.
  3. At each time from zero through t0t_0, no zero between horizontal positions XX and X+1−y02X+\sqrt{1-y_0^2} and heights y02+2(t0−t)\sqrt{y_0^2+2(t_0-t)} and 1−2t\sqrt{1-2t}.

The candidate transcribes these domains correctly. The published height exceeds X/2X/2 by 350479773/2350479773/2. Since y0>0y_0>0, critical-line zeros cannot enter the first domain. The real axis endpoint is also safe: the alternating eta series is positive for real arguments strictly between zero and one, while its factor 1−21−s1-2^{1-s} is negative. Zeta therefore has no zero there; at one it has a pole. This proves the first input using the published theorem.

The closed zero-time endpoint

The positive-time restriction in Polymath Theorem 1.3 does not, by itself, invalidate this candidate. Here is the needed compact-set argument.

Let R=[X,X+1]+i[1809/10000,1]R=[X,X+1]+i[1809/10000,1]. For z∈Rz\in R, u≥0u\ge0, and 0≤t≤t00\le t\le t_0, the integrand defining the heat-deformed function obeys

∣etu2Φ(u)cos⁡(zu)∣≤et0u2+u∣Φ(u)∣.|e^{tu^2}\Phi(u)\cos(zu)|\le e^{t_0u^2+u}|\Phi(u)|.

The series defining Φ\Phi has super-exponential decay as uu tends to infinity, so the right side is integrable. Dominated convergence gives continuity in both time and position, including time zero.

The normalizing factor in the paper is

Bt(z)=Mt((1−iz)/2),Mt(s)=etα(s)2/4M0(s).B_t(z)=M_t((1-iz)/2),\qquad M_t(s)=e^{t\alpha(s)^2/4}M_0(s).

On this rectangle the argument stays away from the branch cut and from zero and one. The explicit factors of M0M_0 and the exponential never vanish. Thus BtB_t and its reciprocal are continuous on the compact time rectangle. The candidate checks that the integer Riemann–Siegel index stays equal to 690988 throughout it. Its approximation ftf_t is consequently a fixed finite sum of continuous functions, without an index jump.

If the positive-time error has the uniform upper bound EE on this box, then for each fixed zz one may pass to the limit in ∣Ht(z)/Bt(z)−ft(z)∣≤E|H_t(z)/B_t(z)-f_t(z)|\le E as time decreases to zero. The same estimate holds at zero. A common constant EE gives the result for every point of the rectangle. No uniform asymptotic limit as xx tends to infinity is used. The identical reasoning applies to the finite-sum derivative bounds.

This resolves the specific zero-time scope note in q1 at the level of analysis. It does not verify the numerical value of EE by itself.

Horizontal window transfer

At fixed positive time, the windows have endpoints xN=4π(N2−t0/16)x_N=4\pi(N^2-t_0/16). They increase strictly and their half-open assignment matches the floor defining the index. The first required point lies inside the first window; the last finite window overlaps the tail, which starts at index 3840000.

The bounds for ∣γ∣|\gamma| and ∣κ∣|\kappa| decrease with horizontal position. For the real-part minorant, write

h(x,y)=1−3y+4y(1+y)/x2.h(x,y)=1-3y+4y(1+y)/x^2.

For nonnegative height, both h+h_+ and x−2x^{-2} are nonnegative and nonincreasing in xx. Their product is nonincreasing. The logarithmic term in the minorant increases, so the whole minorant increases even at the kink. Freezing all three quantities at the left endpoint is therefore conservative. This argument was checked against the producer's formulas.

Native convolution and the sign of the numerator

The real Euler coefficients must be products of the individual prime heat weights, with Möbius signs. Using the heat weight at the composite divisor instead would change the functional. The producer uses the products.

Multiplying the first Dirichlet sum by E(s∗)E(s_*) and the second by its complex conjugate gives two real-coefficient convolutions. The second conjugate is necessary; the candidate includes it. If QQ denotes one minus the gamma bound and the two absolute convolution masses, then the triangle inequality gives

∣E∣ ∣ft∣≥Q−∣E∣ gC,|E|\,|f_t|\ge Q-|E|\,gC,

where gCgC bounds the kappa correction. A positive candidate row says Q/M−gC>0Q/M-gC>0 with M>0M>0 and gC≥0gC\ge0. Thus Q>0Q>0. The displayed inequality first excludes E=0E=0, and then division and ∣E∣≤M|E|\le M imply

∣ft∣≥Q/∣E∣−gC≥Q/M−gC.|f_t|\ge Q/|E|-gC\ge Q/M-gC.

This checks the normalization and the otherwise delicate inequality direction. The Rust implementation recomputes this native functional directly, without frozen weights or Taylor moments.

Height transfer

The height transfer cannot be replaced by a statement that each signed coefficient has a fixed sign. An absolute value can have a kink. For an analytic real function AA, the upper right derivative of ∣A∣|A| at a zero is ∣A′∣|A'|. Away from a zero it is sgn⁡(A)A′\operatorname{sgn}(A)A'. These facts justify the candidate's upper Dini estimate, including its negative gamma-derivative term. The composite divisor kernel retains the sum of the squares of the individual prime logarithms.

The divisor-pattern reduction has 3k3^k cells for kk primes: for each gcd mask, the active divisors form a suffix of its sorted divisor list. The empty suffix contributes zero. The candidate's source checks outward coverage of its logarithmic endpoints and both height endpoints, and splits closed rectangles without gaps.

The local-to-global argument is valid conditional on every numerical cell gate: absolute values of analytic functions and the clipped exponent are locally Lipschitz; on the compact interval they are absolutely continuous. A nonpositive derivative almost everywhere then gives nonincrease. The normalizer decreases with height, and the candidate separately bounds the correction's logarithmic derivative. These are distinct obligations.

The source-level reduction has been reviewed here. A stored cell summary or a repeated precision of that source is not a second implementation of the complete reduction.

The barrier polynomial represents the required finite sum

This is a separate algebraic check from reproducing the coefficient file. Set a=log⁡(N/2)a=\log(N/2), β=(1−i(X+1/2))/2\beta=(1-i(X+1/2))/2, and ℓn=log⁡n−a\ell_n=\log n-a. The regenerated matrix entries are exactly the finite sums

ce,j=∑n=1Nn−βℓnee!(ℓn2/4)jj!.c_{e,j}=\sum_{n=1}^N n^{-\beta} \frac{\ell_n^e}{e!}\frac{(\ell_n^2/4)^j}{j!}.

After the two exponential series are restored, evaluating this matrix at (w,t)(w,t) represents

P(w,t)=∑n=1Nn−βexp⁡(wℓn+tℓn2/4).P(w,t)=\sum_{n=1}^N n^{-\beta} \exp(w\ell_n+t\ell_n^2/4).

For any argument uu used by the code, put v=β−u−tα(u)/2v=\beta-u-t\alpha(u)/2. Expanding the square and collecting the log⁡n\log n and aa terms gives the exact identity

ea(v+ta/4)P(v+ta/2,t)=∑n=1Nbt(n)n−u−tα(u)/2.e^{a(v+ta/4)}P(v+ta/2,t) =\sum_{n=1}^N b_t(n)n^{-u-t\alpha(u)/2}.

This checks the outer powers as well as both shifts in the polynomial argument. In the source, s=(1-y+ix)/2. The bsums branch takes u=1−su=1-s; the asums branch takes u=s‾u=\overline s and is conjugated afterwards. The multiplier afac equals Mt(s)/Mt(1−s)=γM_t(s)/M_t(1-s)=\gamma; the constant normalization difference between H01 and the paper's M0M_0 cancels in this ratio. Since

s∗‾+κ−y=s+t2α(s),\overline{s_*}+\kappa-y=s+\frac t2\alpha(s),

the final bsums + afac*conj(asums) is exactly the ftf_t in Polymath equation (14), up to the separately enclosed two-series remainder.

The remainder proof has positive geometric denominators: here ∣ℓn∣≤log⁡345494<13|\ell_n|\leq\log345494<13, so its quantities A=0.66∣ℓn∣A=0.66|\ell_n| and B=0.05ℓn2B=0.05\ell_n^2 satisfy A<8.58<63A<8.58<63 and B<8.45<63B<8.45<63. For the first omitted term 62, both 1−A/631-A/63 and 1−B/631-B/63 are positive. The rectangular product remainder is bounded by eBIA+eAIBe^B I_A+e^A I_B, where IA,IBI_A,I_B are the two geometric factorial tails. The bound on the combined outer prefactors is deliberately loose but conservative. The separate uniform interval calculation checks both alpha arguments and the exact gamma multiplier on the whole box.

Tail and barrier review

The tail's fixed-left endpoint cap follows from decreasing summands and convexity after the change of variable v=log⁡uv=\log u. Its convolution split is a partition of pairs (d,m)(d,m) according to whether dmdm exceeds the head cutoff. The extra overshoot term is nonnegative padding. The monotonicity gates for the error head must use their own cutoff, rather than the convolution cutoff; the pinned source distinguishes them.

The barrier's interpolation factor of one half is valid. On each half of a spatial mesh edge, the true image and the endpoint chord lie in the same disk around the nearer endpoint, with radius at most half the derivative bound times the edge length. Convexity of that disk gives a zero-avoiding homotopy whenever the full spatial, time, and approximation allowance is smaller than the endpoint modulus. The winding integer is then preserved, and the argument principle applies because BtB_t has neither zeros nor poles there.

The pinned C source checks the time derivative on a whole closed prism, uses the correct mesh denominator, includes the closing polygon edge, and requires strict interval comparisons. Its quadrature callbacks keep complex arguments when an analytic enclosure is requested. The finite head plus decreasing integral tail addresses the discrete-sum issue.

The coefficient generator also has an older quadrature used to choose the number of Taylor terms. Its projection of complex inputs is not a certified holomorphic quadrature. It is not needed as an error estimate here: after the size is selected, every coefficient is a finite Arb sum, and a separate factorial remainder calculation proves that the selected 62-by-62 size suffices. Both the matrix containment check and that independent remainder are mandatory. The derivative-bound quadratures used by the barrier have the repaired complex callbacks described above.

The error constant used in all current candidate lanes is the conservative 179/50+173/25=21/2179/50+173/25=21/2. It follows from Proposition 6.6(vi) by replacing x−8.52x-8.52 with the smaller positive denominator x−12x-12 and using 1+u≤eu1+u\le e^u. The candidate does not need to recover the displayed 10.44 constant in equation (24).

What this review establishes

The parameter transfer, zero-time limit, window directions, native normalization, height reduction, tail reduction, and boundary homotopy withstand this review. Two complete finite implementations have now checked every required index; the second uses the interpolation theorem proved in INTERPOLATION.md. The fresh analytic replay and its exact-rational interface checker have also finished successfully. Together these establish the inequality in CLAIM.md, using the cited published theorems.

The review is by GPT-6 Astra, separately from the candidate's supplied proof notes. It is not a report of external human review. The numerical implementations share Arb where stated; repeating a precision does not create a second implementation.