English

A lower bound for the variance in arithmetic progressions of some multiplicative functions close to $1$

Number Theory 2021-02-23 v1

Abstract

We investigate lower bounds for the variance in arithmetic progressions of certain multiplicative functions "close" to 11. Specifically, we consider αN\alpha_N-fold divisor functions, when αN\alpha_N is a sequence of positive real numbers approaching 11 in a suitable way or αN=1\alpha_N=1, and the indicator of yy-smooth numbers, for suitably large parameters yy. As a corollary, we will strengthen a previous author's result on the first subject and obtain matching lower bounds to some Barban-Davenport-Halberstam type theorems for yy-smooth numbers. Incidentally, we will also find a lower bound for the variance in arithmetic progressions of the prime factors counting functions ω(n)\omega(n) and Ω(n)\Omega(n).

Keywords

Cite

@article{arxiv.2102.10589,
  title  = {A lower bound for the variance in arithmetic progressions of some multiplicative functions close to $1$},
  author = {Daniele Mastrostefano},
  journal= {arXiv preprint arXiv:2102.10589},
  year   = {2021}
}