English

Improved bounds for the two-point logarithmic Chowla conjecture

Number Theory 2025-12-02 v2 Combinatorics

Abstract

Let λ\lambda be the Liouville function, defined as λ(n):=(1)Ω(n)\lambda(n) := (-1)^{\Omega(n)} where Ω(n)\Omega(n) is the number of prime factors of nn with multiplicity. In 2021, Helfgott and Radziwi{\l}{\l} proved that nx1nλ(n)λ(n+1)logx(loglogx)1/2,\sum_{n\leq x} \frac{1}{n} \lambda(n) \lambda(n+1) \ll \frac{\log x}{(\log \log x)^{1/2}},improving earlier results by Tao and Ter\"av\"ainen. We prove that nx1nλ(n)λ(n+1)(logx)1c\sum_{n\leq x} \frac{1}{n} \lambda(n) \lambda(n+1) \ll (\log x)^{1-c}for some absolute constant c>0c>0. This appears to be best possible with current methods.

Keywords

Cite

@article{arxiv.2310.19357,
  title  = {Improved bounds for the two-point logarithmic Chowla conjecture},
  author = {Cédric Pilatte},
  journal= {arXiv preprint arXiv:2310.19357},
  year   = {2025}
}

Comments

A fairly significant reworking of the paper, introducing non-backtracking operators. This simplifies the argument and fixes an issue in Lemma C.1 of version 1. 66 pages

R2 v1 2026-06-28T13:05:37.646Z