CU Algebraic Lie Theory Seminar

CU Algebraic Lie Theory Seminar

Supercharacters and combinatorial Hopf algebras


Nat Thiem, CU

August 31 and September 7, 2010


Math 350

2-3pm

Abstract


At a recent AIM workshop, the participants found a remarkable connection between two seemingly disparate structures: supercharacters, a useful way of doing Fourier analysis on the group of unipotent uppertriangular matrices with coefficients in a finite field, and the ring of symmetric functions in noncommuting variables. Each is a Hopf algebra and the two are Hopf isomorphic. The identification suggests a rich class of examples for the emerging field of combinatorial Hopf algebras. This talk will be in two parts: (1) I will give an introduction to combinatorial Hopf algebras with our favorite examples (2) I will describe supercharacters and how they connect up to one of our favorite Hopf algebras.