Combinatorics Seminar

When: Sunday, December 6, 10am Where: Schreiber 309 Speaker: Konstantin Golubev, Hebrew University Title: Simplicial Complexes of High Chromatic Number

Abstract:

Ramanujan graphs, constructed by Lubotzky, Phillips and Sarnak and known as the LPS graphs, form a family of explicitly constructed graphs of high girth and high chromatic number. High dimensional counterparts of the LPS graphs are the Ramanujan Complexes, constructed by Lubotzky, Samuels and Vishne. They were recently proved to have high chromatic number. In my talk, I will concentrate on the combinatorial part of the proof of this result.

Based on a joint work with S.Evra, A.Lubotzky and O.Parzanchevski.