Date & Time: Wednesday, November 19, 2014, 16:00-17:00.
Venue: Ramanujan Hall
Speaker: Alex Gorodnik, University of Bristol
Title: Diophantine approximation by orbits
Abstract: The classical theory of Diophantine approximation quantifies the density of rational number in the real line. In a joint work with A. Ghosh and A. Nevo we consider an analogous problem of approximating by dense orbits for group actions. We explain a general approach which allows to establish quantitative density and gives the best possible exponents of approximation in a number of cases.