English

A smooth shift approach for a Ramanujan expansion

Number Theory 2019-04-15 v3

Abstract

All arithmetical functions FF satisfying Ramanujan Conjecture, i.e., F(n)εnεF(n)\ll_{\varepsilon}n^{\varepsilon}, and with QQ-smooth divisors, i.e., with Eratosthenes transform F:=FμF':=F\ast \mu supported in QQ-smooth numbers, have a kind of unique Ramanujan expansion; also, these Ramanujan coefficients decay very well to 00 and have two explicit expressions (in the style of Carmichael and Wintner). This general result, then, is applied to the shift-Ramanujan expansions, i.e., the expansions for correlations with respect to the shift, whence the title.

Keywords

Cite

@article{arxiv.1901.01584,
  title  = {A smooth shift approach for a Ramanujan expansion},
  author = {Giovanni Coppola},
  journal= {arXiv preprint arXiv:1901.01584},
  year   = {2019}
}

Comments

Giving counterexamples for the Reef to hold, we disprove Conjectures 1 & 2 (see version 2)

R2 v1 2026-06-23T07:04:12.583Z