is a Professor at the Mathematics Department at UCLA. Before coming here, he was teaching at University of Minnesota and at MIT. Prior to that, he was a Gibbs Instructor at Yale University and a Postdoctoral Fellow at MSRI. He got his Ph.D. from Harvard University. He did his undergraduate studies at Moscow State University. He works in Discrete Mathematics (Discrete and Polyhedral Geometry,Enumerative and Algebraic Combinatorics, Probability and Computations on Groups).