School of Mathematics

Local Testing and Decoding of Sparse Linear Codes

Shubhangi Saraf
Massachusetts Institute of Technology
February 22, 2011

We study the local testabilty of sparse linear codes. This problem is intimately connected to the problem of tolerant linearity testing of Boolean functions under nonuniform distributions. We give linearity tests for several natural and interesting classes of distributions, and use this to show local testability for the corresponding codes.

An Elementary Proof of Anti-Concentration of Polynomials in Gaussian Variables

Shachar Lovett
Institute for Advanced Study
February 14, 2011

Recently there has been much interest in polynomial threshold functions in the context of learning theory, structural results and pseudorandomness. A crucial ingredient in these works is the understanding of the distribution of low-degree multivariate polynomials evaluated over normally distributed inputs. In particular, the two important properties are exponential tail decay and anti-concentration.

Some Equations and Games in Evolutionary Biology

Christine Taylor
Harvard University; Member, School of Mathematics
February 14, 2011

The basic ingredients of Darwinian evolution, selection and mutation, are very well described by simple mathematical models. In 1973, John Maynard Smith linked game theory with evolutionary processes through the concept of evolutionarily stable strategy. Since then, cooperation has become the third fundamental pillar of evolution. I will discuss, with examples from evolutionary biology and ecology, the roles played by replicator equations (deterministic and stochastic) and cooperative dilemma games in our understanding of evolution.