Average Case to Worst Case Reductions for Polynomials

COMPUTER SCIENCE/DISCRETE MATH I
Topic:Average Case to Worst Case Reductions for Polynomials
Speaker:Shachar Lovett
Affiliation:Hebrew University of Jerusalem
Date:Monday, October 13
Time/Room:11:15am - 12:15pm/S-101

We study the model of approximation and calculation of constant degree multivariate polynomials over finite fields. We prove that if a constant degree polynomial can be approximated by a function of a constant number of lower degree polynomials, it can in fact be computed exactly by a function of a constant number of lower degree polynomials. This shows that in this model, approximation and exact calculation are qualitatively equivalent. The technical part of the work is a generalization of a theorem of Green & Tao, showing a structure-randomness dichotomy for constant degree multivariate polynomials.