Wiki
Wiki

Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.

Updated


Statement

Setting (p. 1). A kk-tuple of linear forms H(x)={gjx+hj}j=1k\mathcal H(x)=\{g_jx+h_j\}_{j=1}^k in Z[x]\mathbb Z[x] is admissible when the polynomial ∏j=1k(gjx+hj)\prod_{j=1}^k(g_jx+h_j) has no fixed prime divisor, that is, for every prime pp the number of residues n mod pn \bmod p at which it vanishes mod pp is less than pp. The paper considers only tuples with g1,…,gk>0g_1,\ldots,g_k>0 and ∏1≤i<j≤k(gihj−gjhi)≠0\prod_{1\le i<j\le k}(g_ih_j-g_jh_i)\ne0, its condition (1).

The input (p. 1) is the Maynard-Tao theorem in Granville's formulation, which the paper quotes and does not prove: for every m∈Nm\in\mathbb N with m≥2m\ge2 there is kmk_m, depending only on mm, such that for every integer k≥kmk\ge k_m and every admissible {gjx+hj}j=1k\{g_jx+h_j\}_{j=1}^k satisfying (1), the set {gjn+hj}j=1k\{g_jn+h_j\}_{j=1}^k contains mm primes for infinitely many n∈Nn\in\mathbb N; one may take any kmk_m with kmlog⁡km>e8m+4k_m\log k_m>e^{8m+4}.

Theorem 1 (p. 2). Let m,k∈Nm,k\in\mathbb N with m≥2m\ge2 and k≥kmk\ge k_m, kmk_m as in the Maynard-Tao theorem. Let b1,…,bkb_1,\ldots,b_k be distinct integers with {x+bj}j=1k\{x+b_j\}_{j=1}^k admissible, and let gg be a positive integer coprime to b1⋯bkb_1\cdots b_k. Then there is a subset {h1,…,hm}⊆{b1,…,bk}\{h_1,\ldots,h_m\}\subseteq\{b_1,\ldots,b_k\} such that, for infinitely many n∈Nn\in\mathbb N, the numbers gn+h1,…,gn+hmgn+h_1,\ldots,gn+h_m are consecutive primes.

The paper notes (p. 2) that the case m=2m=2, g=1g=1, with the weaker bound k2≥3.5×106k_2\ge3.5\times10^6, was proved earlier by Pintz by a different argument.

Proof pointer

Pp. 3-4. After shifting so that 1<b1<⋯<bk1<b_1<\cdots<b_k, each integer tt in [1,bk][1,b_k] that is not a bjb_j is assigned its own prime qtq_t, coprime to gg and with t≢bj mod qtt\not\equiv b_j \bmod q_t for every jj; the Chinese remainder theorem gives aa with ga+t≡0 mod qtga+t\equiv0 \bmod q_t for all such tt. With Q=∏qtQ=\prod q_t, the tuple {gQx+ga+bj}\{gQx+ga+b_j\} is admissible and satisfies (1), and every prime in [g(QN+a)+b1, g(QN+a)+bk][g(QN+a)+b_1,\,g(QN+a)+b_k] is one of its values. Taking the largest m′m' such that some m′m' of these forms are simultaneously prime for infinitely many NN, the Maynard-Tao theorem gives m′≥mm'\ge m, and maximality forces the remaining forms to be composite for all large such NN, so those m′m' primes are consecutive.

Read depth

Claims checked: the definitions, the quoted Maynard-Tao statement and Theorem 1 were read clause by clause on the page images of the arXiv print, and the proof on pp. 3-4 was followed. The Maynard-Tao theorem is cited, not proved, in the paper and was not checked here. Nothing here is independently reviewed.

Dependencies

None in the corpus. External input: the Maynard-Tao theorem (Maynard, Small gaps between primes, Ann. of Math. (2) 181 (2015); Granville's formulation, Theorem 6.2 of Primes in intervals of bounded length); Maynard's paper has its own library card.

Source. W. D. Banks, T. Freiberg and C. L. Turnage-Butterbaugh, Consecutive primes in tuples, Acta Arith. 167 (2015), no. 3, 261-266, doi:10.4064/aa167-3-4, arXiv:1311.7003; the edition read and its page numbering are named on the source card.

Bears on

  • Problem 6: the theorem is the step from which the paper's Corollary 1 is deduced; on its own it orders no gaps.