English

Partial sums of biased random multiplicative functions

Number Theory 2019-11-22 v2 Probability

Abstract

Let P\mathcal{P} be the set of the primes. We consider a class of random multiplicative functions ff supported on the squarefree integers, such that {f(p)}pP\{f(p)\}_{p\in\mathcal{P}} form a sequence of ±1\pm1 valued independent random variables with Ef(p)<0\mathbb{E} f(p)<0, pP\forall p\in \mathcal{P}. The function ff is called strongly biased (towards classical M\"obius function), if pPf(p)p=\sum_{p\in\mathcal{P}}\frac{f(p)}{p}=-\infty a.s., and it is weakly biased if pPf(p)p\sum_{p\in\mathcal{P}}\frac{f(p)}{p} converges a.s. Let Mf(x):=nxf(n)M_f(x):=\sum_{n\leq x}f(n). We establish a number of necessary and sufficient conditions for Mf(x)=o(x1α)M_f(x)=o(x^{1-\alpha}) for some α>0\alpha>0, a.s., when ff is strongly or weakly biased, and prove that the Riemann Hypothesis holds if and only if Mfα(x)=o(x1/2+ϵ)M_{f_\alpha}(x)=o(x^{1/2+\epsilon}) for all ϵ>0\epsilon>0 a.s., for each α>0\alpha>0, where {fα}α\{f_\alpha \}_\alpha is a certain family of weakly biased random multiplicative functions.

Keywords

Cite

@article{arxiv.1412.1157,
  title  = {Partial sums of biased random multiplicative functions},
  author = {Marco Aymone and Vladas Sidoravicius},
  journal= {arXiv preprint arXiv:1412.1157},
  year   = {2019}
}

Comments

29 pages, Corrected typos, new section with concluding remarks

R2 v1 2026-06-22T07:18:40.404Z