The distance to square-free polynomials

Speaker: 

Min Sha

Affiliation: 

Macquarie University

Date: 

Wed, 22/08/2018 - 2:00pm

Venue: 

RC-4082, The Red Centre, UNSW

Abstract: 

Given an integer polynomial $f$, let $L(f)$ be the sum of the absolute values of the coefficients of $f$. In 1960s, Turán asked whether there exists an absolute constant $C$ such that for any integer polynomial $f$ of degree $d$,  there is an irreducible integer polynomial $g$ of degree at most d satisfying $L(f-g) < C$. Turán's problem remains open, although a number of partial results have been obtained.

In this talk, I will present some recent work on a variant of Turán's problem. For example, we prove that for any integer polynomial $f$, there exist infinitely many square-free integer polynomials $g$ such that $L(f-g) < 3$. On the other hand, we show that this inequality cannot be replaced by $L(f-g) < 2$. (This is joint work with Artūras Dubickas)

School Seminar Series: