English

On a Tur\'an conjecture and random multiplicative functions

Number Theory 2022-12-06 v3 Probability

Abstract

We show that if ff is the random completely multiplicative function, the probability that nxf(n)n\sum_{n\le x}\frac{f(n)}{n} is positive for every xx is at least 110451-10^{-45}, while also strictly smaller than 11. For large xx, we prove an asymptotic upper bound of O(exp(exp(logxCloglogx)))O(\exp(-\exp( \frac{\log x}{C\log \log x }))) on the exceptional probability that a particular truncation is negative, where CC is some positive constant.

Keywords

Cite

@article{arxiv.2205.05822,
  title  = {On a Tur\'an conjecture and random multiplicative functions},
  author = {Rodrigo Angelo and Max Wenqiang Xu},
  journal= {arXiv preprint arXiv:2205.05822},
  year   = {2022}
}

Comments

V3: accepted version, typos and minor mistakes corrected

R2 v1 2026-06-24T11:14:55.778Z