Wiki
Wiki

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

Updated


Source. Definition 1.1, p. 2, of Alexandru Pascadi, On the exponents of distribution of primes and smooth numbers, arXiv:2505.00653v2 (29 June 2025), the version named on the source card. A preprint. The paper recalls the definition from Maynard's work on primes in arithmetic progressions to large moduli.

Read depth. Claims checked: the definition was read clause by clause on the page image. Nothing here is independently reviewed.

Statement

Definition 1.1 (p. 2). A complex sequence (λq)q≤Q(\lambda_q)_{q\le Q} is triply-well-factorable of level QQ when, for every choice of Q1,Q2,Q3≥1Q_1,Q_2,Q_3\ge1 with Q1Q2Q3=QQ_1Q_2Q_3=Q, there are 1-bounded complex sequences (αq1)(\alpha_{q_1}), (βq2)(\beta_{q_2}), (γq3)(\gamma_{q_3}) supported on qi≤Qiq_i\le Q_i such that for every qq

λq=∑q1q2q3=qαq1βq2γq3.\lambda_q=\sum_{q_1q_2q_3=q}\alpha_{q_1}\beta_{q_2}\gamma_{q_3}.

The paper notes (p. 2) that such weights arise in a slight variant of the β\beta-sieve with β≥2\beta\ge2, and (p. 24) that Iwaniec's well-factorable linear sieve weights factor in two pieces at every split but are not triply-well-factorable in this sense.

Dependencies

None.

Bears on

No Erdős problem page in the corpus links this definition. It is the weight class of Theorem 1.3 (i).