Erdős problem #1137 — wave6v report
Access date: 2026-07-27 UTC.
Outcome: partial progress, not a solution. The useful outputs are an exact
reduction to the established “chains of large gaps” quantity, a rigorous
corollary of the Ford–Maynard–Tao theorem, an exact computation through the
first \(10^7\) prime gaps, and a precise description of the remaining wall.
Claim labels
- (a) elementary-rigorous: proved here from definitions or by an exact
finite argument.
- (b) rigorous-modulo-named-theorem: the deduction is rigorous assuming
the accurately quoted published/preprint theorem.
- (c) plausible/structural-unverified: heuristic only.
- (d) computational-only: exact for the stated finite range, with
reproducible code, but not an asymptotic theorem.
Step 0: authoritative live-page check
I fetched both the live problem page and its discussion thread through the
Bright Data browser path. Direct curl was not used as a substitute. The live
page at <https://www.erdosproblems.com/1137> says:
- status: OPEN;
- claimed proofs: 0;
- “Currently working on this problem”: None;
- “Interested in collaborating”: None;
- three comments;
- last edited 23 January 2026;
- citation: \([{\rm Va99},1.2]\);
- related OEIS entries: A083550 and A005250.
Thus no mandatory stop condition fired.
Verbatim statement from the live LaTeX-source page
Let $d_n=p_{n+1}-p_n$, where $p_n$ denotes the $n$th prime. Is it true that\[\frac{\max_{n<x}d_{n}d_{n-1}}{(\max_{n<x}d_n)^2}\to 0\]as $x\to \infty$?
This report treats that statement, rather than the tracker tags or stale YAML,
as authoritative.
All three listed comments
The discussion thread is
<https://www.erdosproblems.com/forum/thread/1137>. The site itself warns that
comments are not verified.
1. Przemek Chojecki, 12:24 on 02 February 2026. The substantive comment
says “Heuristically this is not true by Cramer like conjecture.” It models
\(d_n/\log p_n\) by independent mean-one exponentials, predicts the largest
individual normalized gap to be about \(\log N\), the largest adjacent pair
to have both entries about \(\frac12\log N\), and hence predicts a ratio
near \(1/4\).
2. FelixPernegger, 06:57 on 25 January 2026. Notes that the numerator is
the record version of OEIS A083550 and the denominator is the square of
A005250; the site says it was updated in response.
3. old-bielefelder, 11:35 on 25 January 2026. Asks how to see the record
version of an OEIS entry.
There are no listed known theorems on the page beyond the source citation.
Original source and cutoff convention
The cited source really exists:
> Various, Some of Paul’s Favorite Problems, booklet circulated at the
> conference “Paul Erdős and his mathematics”, Budapest, July 1999, problem
> 1.2.
A scan is available at
<https://web.math.pmf.unizg.hr/~vjekovac/EP/Some_of_Pauls_favorite_problems.pdf>.
It defines
\[ D(X)=\max_{p_kconvergence question. If
\[ N(X)=\max\{k:p_k\(N(X)\), and \(N(X)\) assumes every sufficiently large integer value as
\(X\) increases. This equivalence is (a).
For the remainder, set
\[ \begin{aligned} G_N&=\max_{1\le n\le N}d_n,\\ Q_N&=\max_{2\le n\le N}d_{n-1}d_n,\\ R_N&=\frac{Q_N}{G_N^2}. \end{aligned} \]Thus \(R_N\) is exactly the live-page expression at \(x=N+1\).
Exact reduction to chains of two large gaps
Define
\[ H_N=\max_{2\le n\le N}\min(d_{n-1},d_n). \]Proposition
For every \(N\ge2\),
\[ \boxed{\left(\frac{H_N}{G_N}\right)^2 \le R_N \le \frac{H_N}{G_N}.} \]Consequently,
\[ \boxed{R_N\to0\quad\Longleftrightarrow\quad H_N/G_N\to0.} \]Proof (a). Take a pair \(a=d_{n-1}\), \(b=d_n\). Since
\(\max(a,b)\le G_N\) and \(\min(a,b)\le H_N\),
\[ ab=\min(a,b)\max(a,b)\le H_NG_N. \]Taking the maximum over pairs gives \(Q_N\le H_NG_N\). A pair attaining
\(H_N\) has both entries at least \(H_N\), so its product is at least
\(H_N^2\), and \(Q_N\ge H_N^2\). Divide by \(G_N^2\). The two implications
follow respectively from the upper bound and from
\(H_N/G_N\le\sqrt{R_N}\). \(\square\)
This isolates the question exactly: are the largest two consecutive gaps
negligible compared with the largest single gap?
There is also an exact match with the standard notation of
Ford–Maynard–Tao. They define
\[ \mathcal G_k(X)= \max_{p_{m+k}\le X}\min(d_m,\ldots,d_{m+k-1}). \]At \(X=p_{N+1}\),
\[ G_N=\mathcal G_1(X),\qquad H_N=\mathcal G_2(X). \]Therefore problem #1137 is precisely
\[ \mathcal G_2(p_{N+1})/\mathcal G_1(p_{N+1})\to0. \]Relevant primary literature
Chains of large gaps
Ford, Maynard, and Tao, Chains of large gaps between primes,
arXiv:1511.04468, Theorem 1, prove that
for every fixed \(k\) and all sufficiently large \(X\),
\[ \mathcal G_k(X)\gg \frac1{k^2} \frac{\log X\,\log_2X\,\log_4X}{\log_3X}, \]with an absolute effective implied constant. This is exactly about \(H_N\)
when \(k=2\), not merely about isolated large gaps.
Keiju Sono, *An explicit lower bound for large gaps between some consecutive
primes*, arXiv:2404.06951, published in
Le Matematiche 80 (2025), 521–544, makes the constant explicit:
\[ \mathcal G_k(X)\ge \frac{c_{\rm LG}}{k^2} \frac{\log X\,\log_2X\,\log_4X}{\log_3X}, \qquad c_{\rm LG}\ge2.0\times10^{-17}, \]for sufficiently large \(X\).
Let
\[ L(X)=\frac{\log X\,\log_2X\,\log_4X}{\log_3X}. \]At \(X=p_{N+1}\), the exact reduction gives the direct corollary (b)
\[ H_N\ge5.0\times10^{-18}L(X) \]and hence
\[ \boxed{Q_N\ge2.5\times10^{-35}L(X)^2} \]for all sufficiently large \(N\). The threshold implicit in “sufficiently
large” is not supplied numerically, so this is not a finite-range estimate.
Established upper bound for a single gap
Baker, Harman, and Pintz, The Difference Between Consecutive Primes, II,
Proc. London Math. Soc. 83 (2001), 532–562,
prove that \([x-x^{0.525},x]\) contains a prime for all sufficiently large
\(x\). The standard consequence is (b)
\[ \mathcal G_1(X)\ll X^{0.525}. \]This and the chain lower bound do not compare
\(\mathcal G_2(X)\) with the actual value of \(\mathcal G_1(X)\). Their
scales are separated by almost a power of \(X\), so inserting them in the
sandwich gives no nonzero or zero limiting bound.
A July 2026 claimed \(O(\log^2p)\) bound is not usable
Cheng-Ting Wang, On Maximal Prime Gaps,
arXiv:2605.14871v5, revised
23 July 2026, claims
\[ d_n<\frac{13}{3}\log^2p_n \]for all \(n\), and consequently claims Oppermann’s conjecture. This would be
a major improvement over the established published bound. It has no journal
reference, and its supplied argument has a concrete invalid step.
In the proof of Lemma 2.3, lines 143–145 of the HTML version assert that
\[ \frac{\log^2n-\log^22}{2} < \frac{n(\log n+\log\log n)}5 \tag{*} \]forces \(n\le4\). At \(n=195\), however,
\[ \text{left side}=13.662035665348,\qquad \text{right side}=270.488358480434, \]so (*) holds although \(195>4\). More fundamentally, the right side grows
like \(n\log n\), while the left grows like \(\log^2n\). Thus this step cannot
produce the claimed contradiction, and the downstream lemma and theorem are
not proved by the posted argument. This diagnosis is (a); it does not
prove Wang’s stated bound false. I do not use the preprint as a theorem.
Search result
Exact-formula searches, searches for products of adjacent gaps, and searches
through the cited chain literature found no primary source deciding
\(\mathcal G_2(X)/\mathcal G_1(X)\). Baker–Freiberg’s normalized-gap results
and the Ford–Maynard–Tao chain theorem control prescribed polylogarithmic
normalizations, not normalization by the all-time maximal gap. This is an
honest literature miss, not evidence that no such paper can exist.
Exact computation through \(N=10^7\)
The standalone checker is
erdos1137_wave6v_verify.py. It uses only the
Python standard library and generates every prime itself with a segmented
Eratosthenes sieve.
For every cutoff it updates \(G_N,Q_N,H_N\) and checks
\[ H_N^2\le Q_N\le H_NG_N. \]It independently audits every record gap, product, and two-gap chain by:
- checking the prime endpoints with deterministic 64-bit Miller–Rabin;
- finding a trial-division certificate for every integer strictly inside
each asserted prime gap;
- checking that all record values and indices increase as required.
The following is exact; fractions are not rounded in the calculation.
| \(N\) | \(p_{N+1}\) | \(G_N\) | \(H_N\) | \(Q_N\) | \(R_N=Q_N/G_N^2\) |
|---:|---:|---:|---:|---:|---:|
| 10 | 31 | 6 | 4 | 24 | \(2/3=0.666666666667\) |
| 100 | 547 | 18 | 12 | 144 | \(4/9=0.444444444444\) |
| 1,000 | 7,927 | 34 | 20 | 512 | \(128/289=0.442906574394\) |
| 10,000 | 104,743 | 72 | 42 | 2,436 | \(203/432=0.469907407407\) |
| 100,000 | 1,299,721 | 114 | 62 | 4,340 | \(1085/3249=0.333948907356\) |
| 1,000,000 | 15,485,867 | 154 | 98 | 9,800 | \(50/121=0.413223140496\) |
| 10,000,000 | 179,424,691 | 222 | 136 | 22,040 | \(5510/12321=0.447203960717\) |
The checker also determines the exact extrema over every inclusive index
decade:
| inclusive \(N\)-range | exact minimum (first \(N\)) | exact maximum (first \(N\)) |
|---:|---:|---:|
| \([10,100]\) | \(2/7\) at 30 | \(1\) at 16 |
| \([100,10^3]\) | \(3/17\) at 217 | \(4/9\) at 100 |
| \([10^3,10^4]\) | \(5/24\) at 3,385 | \(5/9\) at 1,663 |
| \([10^4,10^5]\) | \(345/1568\) at 31,545 | \(203/432\) at 10,000 |
| \([10^5,10^6]\) | \(1085/5476\) at 149,689 | \(50/121\) at 826,235 |
| \([10^6,10^7]\) | \(2/9\) at 1,319,945 | \(5510/12321\) at 8,040,878 |
In particular, the sharp finite statement (d) is
\[ \boxed{\frac29\le R_N\le\frac{5510}{12321} \quad(10^6\le N\le10^7).} \]Finite data cannot imply that the limiting value is positive.
Endpoint record certificates
At \(N=10^7\):
- the maximal single gap is
\[ G_N=222,\qquad 122164969-122164747=222, \]
first occurring at gap index \(6,957,876\);
- the maximal adjacent product is
\[ Q_N=116\cdot190=22040 \]
at
\[ 142414553,\ 142414669,\ 142414859, \]
with product index \(8,040,878\);
- the maximal adjacent minimum is
\[ H_N=136 \]
at
\[ 163709971,\ 163710121,\ 163710257, \]
whose two gaps are \(150\) and \(136\), at product index \(9,170,830\).
The pair that maximizes the product need not be the pair that maximizes the
minimum; the checker keeps the three record processes separate.
Independent recomputation
The principal run used \(1,048,576\) odd integers per sieve segment. A second
full run used the deliberately incommensurate segment size \(100,003\).
Both produced:
- \(10,000,001\) primes ending at \(p_{10,000,001}=179,424,691\);
- 26 single-gap records, 39 product records, and 24 chain-minimum records;
- SHA-256 of \(d_1,\ldots,d_{10^7}\), each encoded as little-endian unsigned
32-bit:
33d7700aeb812181cd82a6222d27a2876a9ab0fe6afac0ce7f7a28ef83cfaab5;
- the same snapshots and all the same decade extrema.
The expected hash and exact tables are frozen as assertions in the checker.
Each Python run took about 35 seconds on this VM.
Finally, PARI/GP’s independent forprime iterator was run through
179,424,691. It returned, independently of the Python sieve:
10 31 6 24 4 2/3
100 547 18 144 12 4/9
1000 7927 34 512 20 128/289
10000 104743 72 2436 42 203/432
100000 1299721 114 4340 62 1085/3249
1000000 15485867 154 9800 98 50/121
10000000 179424691 222 22040 136 5510/12321
PARI_OK
Columns after \(N,p_{N+1}\) are \(G_N,Q_N,H_N,R_N\).
An additional PARI pass maintained exact cross-products at every one of the
\(10^7\) cutoffs and independently returned all six minimum/maximum fractions
and first-attainment indices in the decade table, ending
PARI_EXTREMA_OK.
Reproduction
From the repository root:
python3 runs/erdos1137_wave6v_verify.py --summary-only
To force the alternative segmentation and save every record:
python3 runs/erdos1137_wave6v_verify.py \
--segment-odds 100003 \
--summary-only \
--json-out /tmp/erdos1137_alt.json
No downloaded prime list, OEIS b-file, or probabilistic prime generator is
used.
The \(1/4\) heuristic is a theorem in the independent-exponential model
This does not prove anything about primes, but it makes the page comment
mathematically precise.
Let \(X_1,X_2,\ldots\) be independent \({\rm Exp}(1)\) variables and define
\[ M_N=\max_{i\le N}X_i,\qquad P_N=\max_{2\le i\le N}X_{i-1}X_i. \]Then (a), for this random model only,
\[ \frac{P_N}{M_N^2}\longrightarrow\frac14 \quad\text{in probability}. \]Indeed, standard union bounds give
\[ M_N/\log N\to1 \]in probability. For \(a>1/2\), AM–GM and the exact
\(\Gamma(2,1)\) tail give
\[ \begin{aligned} \Pr(P_N>a^2\log^2N) &\le N\Pr(X_1+X_2>2a\log N)\\ &=N(1+2a\log N)N^{-2a}\to0. \end{aligned} \]For \(a<1/2\), use the \(\lfloor N/2\rfloor\) disjoint pairs. Each pair has
both entries at least \(a\log N\) with probability \(N^{-2a}\), so the
probability that none does is at most
\[ \exp(-cN^{1-2a})\to0. \]Hence \(\sqrt{P_N}/\log N\to1/2\), proving the claim.
Transferring this conclusion to prime gaps requires uniform extreme-value
independence far beyond anything proved. That transfer is (c).
Exact remaining wall
The reduction shows that there are only two possible asymptotic routes:
- A yes proof needs
\[ \mathcal G_2(X)=o(\mathcal G_1(X)), \]
i.e. an isolation theorem saying that every pair of adjacent large gaps is
negligible compared with the record single gap.
- A no proof needs a constant \(c>0\) and arbitrarily large \(X\) for
which
\[ \mathcal G_2(X)\ge c\,\mathcal G_1(X). \]
Current large-gap machinery constructs two consecutive gaps on the
Erdős–Rankin scale \(L(X)\). It supplies no upper control on all other gaps
below the same \(X\), which is exactly what comparison with
\(\mathcal G_1(X)\) requires. Conversely, short-interval prime theorems bound
each individual gap but do not show that two adjacent gaps enjoy a smaller
bound.
A fixed-offset Hardy–Littlewood prime-tuples conjecture is also insufficient:
the offsets here grow with \(X\), the two intervals between the three primes
must contain no additional primes, and the constructed pair must be compared
uniformly with every gap below \(X\). A quantitative, growing-offset,
prime-free, uniform version would be needed.
Extending the finite scan cannot resolve that uniformity. At the measured
Python rate, \(N=10^8\) would cost about 350 seconds, roughly \(0.10\)
single-core hours, and would reach \(p_N\) near \(2.0\times10^9\). An
optimized compiled segmented sieve would likely reduce that to a few minutes,
but any finite endpoint still leaves the same asymptotic lemma missing, so I
did not spend the box’s few-minute compute budget on it.
PARTIAL: proved the exact equivalence \(R_N\to0\iff\mathcal G_2(p_{N+1})/\mathcal G_1(p_{N+1})\to0\), derived a rigorous chain-theorem lower bound for the numerator, and exactly verified \(2/9\le R_N\le5510/12321\) for every \(10^6\le N\le10^7\); the required asymptotic comparison remains open.