English

Local universality of zeroes of random polynomials

Probability 2014-05-01 v3

Abstract

In this paper, we establish some local universality results concerning the correlation functions of the zeroes of random polynomials with independent coefficients. More precisely, consider two random polynomials f=i=1nciξizif =\sum_{i=1}^n c_i \xi_i z^i and f~=i=1nciξ~izi\tilde f =\sum_{i=1}^n c_i \tilde \xi_i z^i, where the ξi\xi_i and ξ~i\tilde \xi_i are iid random variables that match moments to second order, the coefficients cic_i are deterministic, and the degree parameter nn is large. Our results show, under some light conditions on the coefficients cic_i and the tails of ξi,ξ~i\xi_i, \tilde \xi_i, that the correlation functions of the zeroes of ff and f~\tilde f are approximately the same. As an application, we give some answers to the classical question `"How many zeroes of a random polynomials are real?" for several classes of random polynomial models. Our analysis relies on a general replacement principle, motivated by some recent work in random matrix theory. This principle enables one to compare the correlation functions of two random functions ff and f~\tilde f if their log magnitudes logf,logf~\log |f|, \log|\tilde f| are close in distribution, and if some non-concentration bounds are obeyed.

Keywords

Cite

@article{arxiv.1307.4357,
  title  = {Local universality of zeroes of random polynomials},
  author = {Terence Tao and Van Vu},
  journal= {arXiv preprint arXiv:1307.4357},
  year   = {2014}
}

Comments

56 pages, no figures, to appear, IMRN. A gap in an argument invoking Gromov type theorems (in the treatment of the Kac model) has been fixed