Combinatorics Seminar

When: Sunday, November 23, 10am
Where: Schreiber 309
Speaker: Ido Ben-Eliezer, Tel Aviv University
Title: Random polynomials are almost balanced: Proof and applications

Abstract:

Given a multivariate polynomial p, the bias of p is |\Pr[p(x)=1]-\Pr[p(x)=0]|.

We prove that for large enough n, and d at most cn for some constant c, the bias of a randomly chosen polynomial on n variables of degree d is very small with high probability, thus getting a bound on the weight distribution of Reed-Muller codes.

We also provide two applications of this claim. First, we provide a nearly tight lower bound on the size of distributions that fool low degree polynomials. Second, we prove that a typical low degree polynomial cannot be approximated by polynomials of lower degree.

Based on a joint work with Noga Alon and Michael Krivelevich and a joint work with Rani Hod and Shachar Lovett.