English

Universality for low degree factors of random polynomials over finite fields

Probability 2022-09-07 v2 Combinatorics Number Theory

Abstract

We show that the counts of low degree irreducible factors of a random polynomial ff over Fq\mathbb{F}_q with independent but non-uniform coefficients behave like that of a uniform random polynomial, exhibiting a form of universality for random polynomials over finite fields. Our strongest results require various assumptions on the parameters, but we are able to obtain results requiring only q=pq=p a prime with pexp(n1/13)p\leq \exp({n^{1/13}}) where nn is the degree of the polynomial. Our proofs use Fourier analysis, and rely on tools recently applied by Breuillard and Varj\'u to study the ax+bax+b process, which show equidistribution for f(α)f(\alpha) at a single point. We extend this to handle multiple roots and the Hasse derivatives of ff, which allow us to study the irreducible factors with multiplicity.

Keywords

Cite

@article{arxiv.2201.06156,
  title  = {Universality for low degree factors of random polynomials over finite fields},
  author = {Jimmy He and Huy Tuan Pham and Max Wenqiang Xu},
  journal= {arXiv preprint arXiv:2201.06156},
  year   = {2022}
}

Comments

v2: updated introduction, 34 pages, 4 figures. Comments are welcome!