|Date: Friday, March 15, 2013
Location: 3866 East Hall (4:10 PM to 5:00 PM)
Title: Factoring the characteristic polynomial of a poset
Abstract: Given a poset P, its characteristic polynomial x(P;t) is the generating function in the variable t for the Moebius function of P. For many families of posets, every root of x(P;t) is in the set P of positive integers. A number of different techniques have been devised for showing that x(P;t) factors over P including Zaslavsky's theory of signed graphs, results by Saito and Terao about free hyperplane arrangements, and Stanley's Supersolvability Theorem. We will present a new, totally combinatorial method for proving factorization. This is joint work with Joshua Hallam.
Speaker: Bruce Sagan
Institution: Michigan State University