Speaker : Thomas Lam (Harvard University)
Date : 2008. 9. 8(Mon), 17:00 - 18:00
Place : E6-1 #1409
Title : Total positivity for loop groups.
Abstract:
A (possibly infinite) matrix X is totally non-negative if every finite minor is nonnegative. We study the totally nonnegative part of the loop group GLn(R((t))), by identifying elements of the loop group with infinite
matrices. For n = 1, the problem reduces to the classical Edrei-Thoma classification of totally positive sequences, which is known to be equivalent to the classification of characters of the in nite symmetric group. This is joint work with Pavlo Pylyavskyy.