On the number of non-real zeroes of a homogeneous differential polynomial and a generalization of the Laguerre inequalities

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Tyaglov, Mikhail, Atia, Mohamed J.
Format: Preprint
Published: 2019
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909663251922944
author Tyaglov, Mikhail
Atia, Mohamed J.
author_facet Tyaglov, Mikhail
Atia, Mohamed J.
contents Given a real polynomial $p$ with only real zeroes, we find upper and lower bounds for the number of non-real zeroes of the differential polynomial $$ F_{\varkappa}[p](z):= p(z)p''(z)-\varkappa[p'(z)]^2,$$ where $\varkappa$ is a real number. We also construct a counterexample to a conjecture by B. Shapiro on the number of real zeroes of the polynomial $F_{\tfrac{n-1}{n}}[p](z)$ in the case when the real polynomial $p$ of degree $n$ has non-real zeroes. We formulate some new conjectures generalising the Hawaii conjecture.
format Preprint
id arxiv_https___arxiv_org_abs_1912_04951
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle On the number of non-real zeroes of a homogeneous differential polynomial and a generalization of the Laguerre inequalities
Tyaglov, Mikhail
Atia, Mohamed J.
Classical Analysis and ODEs
Primary 12D10, Secondary 26C10, 26C15, 30C15, 30C10
Given a real polynomial $p$ with only real zeroes, we find upper and lower bounds for the number of non-real zeroes of the differential polynomial $$ F_{\varkappa}[p](z):= p(z)p''(z)-\varkappa[p'(z)]^2,$$ where $\varkappa$ is a real number. We also construct a counterexample to a conjecture by B. Shapiro on the number of real zeroes of the polynomial $F_{\tfrac{n-1}{n}}[p](z)$ in the case when the real polynomial $p$ of degree $n$ has non-real zeroes. We formulate some new conjectures generalising the Hawaii conjecture.
title On the number of non-real zeroes of a homogeneous differential polynomial and a generalization of the Laguerre inequalities
topic Classical Analysis and ODEs
Primary 12D10, Secondary 26C10, 26C15, 30C15, 30C10
url https://arxiv.org/abs/1912.04951