School of Mathematics

Nonlinear Long-Range Resonant Scattering and Kink Dynamics

Avy Soffer
Rutgers, The State University of New Jersey
December 7, 2012

We study the nonlinear Klein-Gordon equation, in one dimension, with a qudratic term and variable coefficient qubic term. This equation arises from the asymptotic stability theory of the kink solution.Our main result is the global existence and decay estimates for this equation. We discovered a striking new phenomena in this problem: a resonant interaction between the spacial frequencies of the nonlinear coefficient and the temporal oscillations of the solution.

Information Complexity and Exact Communication Bounds

Mark Braverman
Princeton University
December 3, 2012

In this talk we will discuss information complexity -- a measure of the amount of information Alice and Bob need to exchange to solve a problem over distributed inputs. We will present an information-theoretically optimal protocol for computing the AND of two bits distributed between Alice and Bob. We prove that the information complexity of AND is ~1.4923 bits. We use the optimal protocol and its properties to obtain tight bounds for the Disjointness problem, showing that the randomized communication complexity of Disjointness on n bits is ~0.4827n ± o(n).