A preprint posted on 23 September 2026 claims that ζ(7) is irrational, by adapting the Hankel-determinant argument that settled ζ(5) a week earlier. The proof rests on one number, A₂₀₀ + U, being negative; the paper prints −11.99. On 3 October a reader, GitHub user @huntrontrakkr, reported that one of its integrals does not follow from the paper's own formulas. We recomputed it in exact arithmetic, with code written here. The reader is right: the number is positive, under every reading of the paper and every correction in its favour that we could decide. That breaks this proof. It does not show that ζ(7) is rational — whether ζ(7) is irrational remains open.
Local working document, machine-derived, not peer-reviewed. Decided: the arithmetic of the paper's proof route, from its formulas as printed, as exact rationals or arb balls — the outer integral, the inner integral (121), the constants A0 and U's ingredients, the margins (117)–(119). Measured, not decided: the paper's own family at three sizes. Not decided: whether ζ(7) is irrational (open); Theorem 1.2 as a statement about large n; the inner estimate Proposition 4.4; Lemma 6.1's supremum; the Lean repository's own theorem, which was read, not built. Nothing was posted, commented or sent.
The paper. P. Anand, Zeta 7 is Irrational, Zenodo 10.5281/zenodo.22920911, v1 (the record's only version), 2026-09-23, 42 pages, CC-BY-4.0. Theorem 1.1: ζ(7) is irrational. The route is Fauzan's for ζ(5): integer polynomials Q built from Hankel determinants of a moment functional that is positive at ζ(7), with lim sup K⁻² log Q(ζ(7)) ≤ A_M + U (117). A_M collects the arithmetic (the primes that can be divided out), U the size of the determinant. The proof needs the sum negative; (118) states A₂₀₀ + U < −11, and Theorem 1.2's rate exp(−19000 n²) comes from it.
The report. On 2026-10-03 GitHub user @huntrontrakkr — a third party, not this lab — opened issue #1 on gmDevi/zeta-7-21-lean, a repository whose README cites the paper, because the paper gives no contact address. The report makes four points: the outer integrand on (1, 37/20] is 37/20 − y, not Table 5's −239/20 − 2y, which alone moves A₂₀₀ + U to +0.95; integrating the paper's (54), (58), (59), (62) gives I_out = 453803/288000, not −11002997/720000; the constant A0 is Fauzan's entire ζ(5) constant; and with all of it, A₂₀₀ + U ≈ +4.86. It says plainly that it concerns only the v1 argument, not whether ζ(7) is irrational. As fetched on 2026-10-05 the issue is open with 0 comments.
What we did. We recomputed each of those points from the paper's printed formulas, with code written here that shares nothing with the paper or with the report's script, and checked it by reproducing a published value that is right: Fauzan's own outer integral, 127751/96000. We also computed the paper's own polynomials exactly at three sizes. The author's Zenodo note mentions a rounding issue in the decay constant, to be fixed in a v2; no v2 has been posted.
Each line is decided from the paper as printed, except the last two, which are its finite statements checked at three sizes. CERTIFIED means the statement holds exactly; REFUTED means it does not; REFUSED means the paper does not establish it, which is not the same as false; PARTIAL means checked only where stated. The kind of defect, where there is one, is an arithmetic slip.
| claim | verdict | the number |
|---|---|---|
| the reader's point 1: the last piece alone moves A₂₀₀ + U to +0.95 | CERTIFIED | +0.9484 |
| the reader's point 2: I_out = 453803/288000 from the formulas | CERTIFIED | 453803/288000 |
| the reader's point 3: A0 is Fauzan's whole ζ(5) constant; (85) bounds that tail by ≈ −0.057 | CERTIFIED | −2069/36000 |
| the reader's total: A₂₀₀ + U ≈ +4.86, or ≈ +3.49 with A0 replaced | CERTIFIED | +4.865 · +3.490 |
| (122) I_out = −11002997/720000 follows from the paper's formulas | REFUTED | it is Table 5's integral |
| Table 5, last row: −239/20 − 2y on [1, 37/20] | REFUTED | it is 37/20 − y |
| (118) A₂₀₀ + U < −11, the inequality the proof rests on | REFUTED | +4.865 |
| (119) A₁₀₀₀₀₀ + U < −12, used for the irrationality measure | REFUTED | +4.824 |
| Theorem 1.2, the decay exp(−19000 n²): its proof | REFUTED | proof only; see §5 |
| Theorem 1.1: ζ(7) is irrational | REFUSED | not proved here; open |
| Corollary 1.3: |ζ(7) − a/b| > b⁻²⁷⁰ | REFUSED | rests on (119) |
| (121) the inner integral, from (64)–(69) | CERTIFIED | exact, as printed |
| (96) U = 44/25 bounds λM0 − I(ρ) + C* | CERTIFIED | holds; the printed I(ρ) is mis-summed |
| Proposition 4.6, the local bound (59), at K = 40, 80, 120 | PARTIAL | holds at every prime tested |
| Proposition 6.3, the real bound, at K = 40, 80, 120 | PARTIAL | holds |
The outer primes, K/3 < p ≤ 2h, enter through an exponent Lp = vp(SK) + γpout (60): the factorials of the normalisation (62) and the local bound (59). In the variable y = p/K, −Lp/K tends to a piecewise-linear function T(y), and I_out is its integral over [1/3, 37/20]. The paper's Appendix A.2 gives T as Table 5 and its integral as (122).
Past y = 1 there is nothing to compute. The paper sets γpout = 0 for p > K (§5.1); K!, N! and 4 are units at such p; only the factorials (2i)! of SK carry p, and they carry it in the denominator. So Lp = −(2h − p − 1) < 0 and T(y) = 37/20 − y, which is positive. Table 5 prints −239/20 − 2y, about −14. That one row is worth +12.94 in I_out. Across the rest of the range the table is wrong as well, by +3.92.
| Table 5 interval | Table 5 gives | formulas, reading R2 | formulas, reading R1 |
|---|---|---|---|
| [1/3, 37/100] | −0.2406 | +0.1679 | +0.1569 |
| [37/100, 37/80] | −0.5286 | +0.3022 | +0.2839 |
| [37/80, 29/60] | −0.0993 | +0.0460 | +0.0454 |
| [29/60, 1/2] | −0.0732 | +0.0360 | +0.0360 |
| [1/2, 37/60] | −0.6621 | +0.4233 | +0.4233 |
| [37/60, 37/40] | −1.0175 | +0.3083 | +0.3083 |
| [37/40, 77/80] | −0.0445 | −0.0333 | −0.0333 |
| [77/80, 1] | −0.0361 | −0.0361 | −0.0361 |
| [1, 37/20] | −12.5800 | +0.3613 | +0.3613 |
| [1/3, 37/20] | −15.2819 | +1.5757 | +1.5457 |
The paper defines R0 twice, inconsistently: (71) makes it the limit of −γ/K, while §5.3 and the proof of Proposition 5.4 say −γ = K(R0 − d) + O(1), so that R0 − d is that limit. R2 follows the proof: the integrand is the limit of the exponents the normalisation (61) actually uses, and its integral is 453803/288000, the reader's value. R1 takes (71) and (73) literally and subtracts d(y) a second time, which lowers I_out by 3/100 and favours the author. It gives 445163/288000. Neither is close to −11002997/720000, which is exactly the integral of Table 5.
A₂₀₀ = A0 + I_out + ∫₃²⁰ R/x³ + (cutoff terms) (88)–(89), and the proof needs A₂₀₀ + U < 0. We recomputed it in every combination: I_out as printed, with only Table 5's last row fixed, and from the formulas under each reading; A0 and U as printed, or corrected in the author's favour where this audit can decide the correction. Two such corrections exist. The paper's A0 (≈ +1.318) is larger than the paper's own tail bound (85) for the quantity it stands for, −2069/36000. And the paper's U overstates its own bound, because (110) sums the comparison measure's energy with the wrong logarithm; correctly summed, λM0 − I(ρ) + C* = +0.5563, not 1.7514.
| I_out | A0, U as printed | A0 → (85), U → 0.556 | A0 → (85), U → measured | best any cutoff can do |
|---|---|---|---|---|
| I_out as printed (122) | −11.993 | −14.572 | −15.853 | −14.613 |
| Table 5 with only its last row corrected | +0.948 | −1.630 | −2.912 | −1.672 |
| from the formulas, reading R2 | +4.865 | +2.286 | +1.005 | +2.245 |
| from the formulas, reading R1 | +4.835 | +2.256 | +0.975 | +2.215 |
Read across a row. With I_out from the formulas, every entry is positive, and the smallest decided one is +2.256. The third column goes further than the audit can decide: it replaces U with the measured value, at n = 3, of the quantity U bounds, −0.725. Even then the entry stays positive. The last column is B0 + U, the floor that A_M + U approaches as the cutoff M grows. A_M > B0 for every M, because (89)'s cutoff terms form a quadratic with negative discriminant, so no choice of M rescues (118). (119), the input to the irrationality measure, fails the same way.
Correcting only the last row moves A₂₀₀ + U from −11.99 to +0.9484, exactly as reported. But that keeps the paper's A0 and U, which are both too large. With them corrected too, the last row alone would leave −1.63 < 0. So the last row does not break the proof by itself. What breaks it is the whole of Table 5, and the formulas decide every row of it.
A failed inequality could mean the bounds are loose while the polynomials are still small. To check, we computed the paper's own determinant exactly: K = 40n, N = 3n, DN8/DK, h = 37n, with our Hankel engine (its functional at k = 7 is the paper's (5)–(6)). We then divided out every common factor. What is left, PK, is the smallest integer polynomial any normalisation can give. The paper's B.3 says its QK,M is a positive-integer multiple of PK. Theorem 1.2 would need log PK(ζ(7))/K² below −11.87 for large n.
| n | K | h | log P(ζ(7))/K² | per h² | log F(ζ(7))/K² | (59) exact at | v_p above K |
|---|---|---|---|---|---|---|---|
| 1 | 40 | 37 | +0.7965 | +0.931 | −0.655 | 4 / 6 | 9 primes · all 0 |
| 2 | 80 | 74 | +0.8712 | +1.018 | −0.707 | 10 / 13 | 12 primes · all 0 |
| 3 | 120 | 111 | +0.8839 | +1.033 | −0.725 | 13 / 18 | 17 primes · all 0 |
The margin is positive at every size and still rising: +0.796, +0.871, +0.884. Per h² it sits near +1.03, the same wall the Hankel-method measurement found for ζ(7) across 323 families. The paper's family was measured here, not assumed to share that wall. The local bound (59) holds at every outer prime tested, and with equality at most. At every prime between K and 2h the exact valuation of ΔK is 0, where Table 5's last row would need about 15K.
Three sizes do not decide a limit in n, and Theorem 1.2 is a limit statement. What the table shows is narrower: the paper's proof is refuted by its own arithmetic (§3–§4), and on these polynomials nothing suggests the theorem's rate. If the route can be saved, it will take a different family, not tighter bounds on this one.
The issue was filed on gmDevi/zeta-7-21-lean because its README cites the paper. The repository does not formalise the paper. Its theorem, at commit 4e48690, is
that is, at least one of ζ(7), ζ(9), …, ζ(21) is irrational, by Zudilin's very-well-poised forms. It does not say which one, and it does not imply that ζ(7) is irrational. Its README cites Anand's paper as background and says its own check could not confirm two constants in the final inequality; that matches what §3 finds.
The audit record (every decided quantity as an exact rational or a ball, both readings, all 24 margin scenarios, the verdicts, the Lean census) · the measured family in certs/zeta7-anand/measure.json · the code in instruments/zeta7audit/ · the sources pinned by sha256 in instruments/zeta7audit/PROVENANCE.json: the paper (CC-BY-4.0, committed), the issue thread as fetched, and, git-ignored, Fauzan's paper and the Lean clone.
Context: the Hankel method, measured past ζ(5), where the same family shape shows a positive margin at ζ(7) across 323 families. That is a measurement, not a theorem. This page decides one paper's proof, which is a narrower thing. The issue is issue #1 by @huntrontrakkr; the credit for finding the error is theirs.