On random polynomials with an intermediate number of real roots

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Michelen, Marcus, O'Rourke, Sean
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909161569124352
author Michelen, Marcus
O'Rourke, Sean
author_facet Michelen, Marcus
O'Rourke, Sean
contents For each $α\in (0, 1)$, we construct a bounded monotone deterministic sequence $(c_k)_{k \geq 0}$ of real numbers so that the number of real roots of the random polynomial $f_n(z) = \sum_{k=0}^n c_k \varepsilon_k z^k$ is $n^{α+ o(1)}$ with probability tending to one as the degree $n$ tends to infinity, where $(\varepsilon_k)$ is a sequence of i.i.d. (real) random variables of finite mean satisfying a mild anti-concentration assumption. In particular, this includes the case when $(\varepsilon_k)$ is a sequence of i.i.d. standard Gaussian or Rademacher random variables. This result confirms a conjecture of O. Nguyen from 2019. More generally, our main results also describe several statistical properties for the number of real roots of $f_n$, including the asymptotic behavior of the variance and a central limit theorem.
format Preprint
id arxiv_https___arxiv_org_abs_2310_16966
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On random polynomials with an intermediate number of real roots
Michelen, Marcus
O'Rourke, Sean
Probability
For each $α\in (0, 1)$, we construct a bounded monotone deterministic sequence $(c_k)_{k \geq 0}$ of real numbers so that the number of real roots of the random polynomial $f_n(z) = \sum_{k=0}^n c_k \varepsilon_k z^k$ is $n^{α+ o(1)}$ with probability tending to one as the degree $n$ tends to infinity, where $(\varepsilon_k)$ is a sequence of i.i.d. (real) random variables of finite mean satisfying a mild anti-concentration assumption. In particular, this includes the case when $(\varepsilon_k)$ is a sequence of i.i.d. standard Gaussian or Rademacher random variables. This result confirms a conjecture of O. Nguyen from 2019. More generally, our main results also describe several statistical properties for the number of real roots of $f_n$, including the asymptotic behavior of the variance and a central limit theorem.
title On random polynomials with an intermediate number of real roots
topic Probability
url https://arxiv.org/abs/2310.16966