### DIMACS - Graduate Student Combinatorics Seminar

Title: An application of topology to a hypergraph problem

Speaker: **Aditya Potukuchi**, Rutgers University

Date: Wednesday, December 6, 2017 12:10pm

Location: Graduate Student Lounge, 7th Floor, Hill Center, Rutgers University, Busch Campus, Piscataway, NJ

Abstract:

The chromatic number of the Kneser graph (conjectured in 1955) was a seemingly difficult open problem until it was solved by Lovasz in 1978 by using quite non-trivial ideas from topology. Using a bit of geometry, Barany (1978) turned this into an extremely short (yet non-trivial!) proof. The main idea of behind talk is to try and understand at least some of the power that is to be gained by using topological ideas to solve problems that seemingly stem (purely!) from combinatorics. In particular, the paper that will be used for this attempt is a paper by Alon-Frankl-Lovasz, who generalize Lovasz's earlier proof to hypergraphs

See: http://www.math.rutgers.edu/~yb165/GCS.html