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Sum-product patterns in the shifted primes

Number Theory · Submitted 2 Oct 2026 · 175 references

Pith's verdict: A genuinely new mixed-additive-multiplicative result in the shifted primes, well-architected and mostly self-contained, but load-bearing on two unpublished companion preprints a referee must verify.

T0 · AI review

How this review was made: An AI referee (deepseek/deepseek-v4-flash) read the paper on October 5, 2026 and answered a fixed list of questions about it. T0 is the starting level every paper gets. The levels describe how deeply Pith has checked the paper, never the authors.

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  5. T4 Proof Those claims proved, and the proof checked by computer.

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arXiv ID2610.03417 (version 1)
Pith IDYS6D5WKT, Pith's permanent record of this paper and its review
CitationFlorian K. Richter, Joni Ter\"{a}v\"{a}inen. "Sum-product patterns in the shifted primes." arXiv:2610.03417 (2026). https://pith.science/paper/YS6D5WKT
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Referee report
The paper

The paper claims

The paper claims $\mathbb{P}-1$ contains $\{x,x+y,xy\}$ for arbitrarily large distinct $x,y$, and $\{x,x+y,\ldots,x+ky,xy\}$ for any fixed $k$, a statement containing the Green–Tao theorem as a special case.

The reading

The paper aims to prove that the shifted primes — the numbers $p-1$ for primes $p$ — contain patterns that mix addition and multiplication: for arbitrarily large distinct $x,y$, each of $x$, $x+y$, and $xy$ is a shifted prime. The stronger form claims the same for $\{x, x+y, \ldots, x+ky, xy\}$ for any fixed $k$, a statement whose progression part alone reproduces the Green–Tao theorem. A reader should care because it exhibits, for the first time, genuinely joint additive–multiplicative structure inside a sparse prime-related set, not just one or the other. The proof is a four-step approximation that swaps the von Mangoldt function for a Siegel-corrected model at two scales and leans on a local Gowers norm estimate imported from a companion preprint.

What carries the argument

The engine is the Siegel model $\tilde{\Lambda}_W(n) = \Lambda_W(n)(1 - \tilde{\chi}(n)n^{\tilde{\beta}-1})$, the truncated von Mangoldt function at level $W = \prod_{p \le w} p$ corrected by a factor built from the Siegel zero $\tilde{\beta}$ and its character $\tilde{\chi}$ at level $w$ (taken as $\tilde{\beta}=1$, $\tilde{\chi}\equiv 0$ when no zero exists). The proof has four steps: replace the $k$ inner factors of $\Lambda$ by $\tilde{\Lambda}_{W_2}$ (Step 1, on the local Gowers norm bound of Theorem 3.2, quoted from a companion preprint); replace the outer factor by the $\tilde{\Lambda}_{W_1}$ model via a Bombieri–Vinogradov estimate with an extra congruence (Step 2, Lemma 3.3); remove the Siegel corrections and pass to a singular series of local densities using sieve and Weil bounds (Step 3); and evaluate the positive main term (Step 4, using a positivity estimate quoted from another preprint). The dilating primes $p_1, \ldots, p_\ell$ are chosen to avoid the Siegel character moduli $Q$, which is what produces the $\tau(D)$ saving in the lower bound.

Extended reading notes

Core claim

The central claim is Theorem 1.6: a weighted count of triples $(d,m,n)$, evaluating the von Mangoldt function at $k+2$ affine forms, is $\gg \tau(D)\varphi(W_1)MN/W_1$ for all large $N$. Since each factor forces a prime value, this lower bound produces many $d,m,n$ with $\Delta dm + 1$, $\Delta^2Dmn + 1$, and $L_j(\Delta dm, \Delta D n/d) + 1$ all prime, and re-labelling $x = \Delta dm$, $y = \Delta D n/d$ yields the patterns $\{x, xy, L_1(x,y), \ldots, L_k(x,y)\}$ inside $\mathbb{P}-1$. From here the paper derives Theorem 1.3 (arbitrary non-proportional linear forms $L_j = a_j x + b_j y$) and Corollary 1.4 ($\{x, x+y, \ldots, x+ky, xy\}$). The authors also state the boundary of their result: finding $\{x,y,xy\}$, let alone $\{x,y,x+y,xy\}$, in $\mathbb{P}-1$ for arbitrarily large $x,y$ would settle a major open problem on the Liouville function, so the pattern's form is essentially the strongest possible.

Load-bearing premise

The load-bearing input is the local Gowers norm bound of Theorem 3.2, that $\Lambda - \tilde{\Lambda}_W$ has small $U^s$-norm on every interval of length at least $X^{5/8+\varepsilon}$, which the paper quotes from a companion preprint without proof here; the first main-term estimate (Proposition 2.2) collapses if that bound is false or holds only under narrower hypotheses.

Editorial extensions

If this is right

  • $\mathbb{P}-1$ contains infinitely many triples $\{x, x+y, xy\}$ with $x,y$ arbitrarily large distinct — this is Theorem 1.1.
  • For every fixed $k$, $\mathbb{P}-1$ contains $\{x, x+y, \ldots, x+ky, xy\}$; dropping the product element leaves the Green–Tao progressions, which Corollary 1.4 contains as a special case.
  • The pattern persists for any family of non-proportional linear forms $L_j(x,y) = a_j x + b_j y$ (Theorem 1.3).
  • The weighted count in (1.5) is bounded below by a positive multiple of $\tau(D)\varphi(W_1)MN/W_1$, so the pattern is not merely present but dense in the natural counting sense.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The four-step approximation is largely modular: any sparse set whose prime-detecting function satisfies the same Gowers and Bombieri–Vinogradov inputs should inherit the same mixed patterns, so the genuinely new ingredient is the product-plus-progression combination rather than this particular set.
  • The interval-length exponent $5/8$ in the imported Gowers bound sets the effective scale of the proof; improving that exponent would likely sharpen the main-term savings or widen the admissible range of the forms, though the paper does not pursue this.
  • A quantitative version for $\mathbb{P}-a$ with general fixed $a$ seems within reach of the same machinery, but the paper itself only treats $\mathbb{P}-1$.
  • Because the Liouville obstruction (Proposition 1.2) blocks any pattern containing both $x$ and $y$ themselves, $\{x, x+y, xy\}$ is plausibly the strongest mixed pattern current methods can extract, and any advance toward $\{x, y, xy\}$ must bypass that obstruction.
Original abstract

We show that the set $\mathbb{P}-1$ of shifted primes contains infinitely many sum-product patterns of the form $\{x,x+y,xy\}$ with $x,y$ arbitrarily large distinct integers. More strongly, we can also show that, for any $k\geq 1$, the set $\mathbb{P}-1$ contains longer patterns of the form $\{x,x+y,\ldots, x+ky,xy\}$ with $x,y$ arbitrarily large distinct integers, a statement that contains the Green--Tao theorem as a special case.

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.

Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-10-05: 1 request, 2,455 input tokens.

What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.06 · human participants 0.01 · controlled comparison 0.01 · randomized assignment 0.01 · states quantitative result 0.23 · compares with prior results 0.80 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; .

We show that the set $\mathbb{P}-1$ of shifted primes contains infinitely many sum-product patterns of the form $\{x,x+y,xy\}$ with $x,y$ arbitrarily large distinct integers. More strongly, we can also show that, for any $k\geq 1$, the set $\mathbb{P}-1$ contains longer patterns of the form $\{x,x+y,\ldots, x+ky,xy\}$ with $x,y$ arbitrarily large distinct integers, a statement that contains the Green--Tao theorem as a special case.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 We show that the set $\mathbb{P}-1$ of shifted primes contains infinitely many sum-product patterns of the form $\{x,x+y,xy\}$ with $x,y$ arbitrarily large distinct integers. result 0.93 0.96 0.80 asserted 1.00
s1 More strongly, we can also show that, for any $k\geq 1$, the set $\mathbb{P}-1$ contains longer patterns of the form $\{x,x+y,\ldots, x+ky,xy\}$ with $x,y$ arbitrarily large distinct integers, a statement that contains the Green--Tao theorem as a special case. result 0.90 0.91 0.39 asserted 0.98

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from proof or derivation 1.00.

What was examined, and what was not

sources read
  • arXiv listing abstract v1
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
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  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

References

Discussion

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