Roy Meshulam

Abstract:    We'll discuss some connections between the expansion constant of a graph and the topology of certain complexes associated with the graph. These results are related to Garland's theorem on the cohomology of p-adic groups. Applications include a lower bound on the homological connectivity of the independence complex, in terms of a new graph domination parameter defined via vector representations of the graph. This in turn implies Hall type theorems for matchings in hypergraphs.

Joint work with R.Aharoni and E. Berger.

Here are some directions to Northeastern University. Lake Hall can be best accessed from the entrance on the corner of Greenleaf Street and Leon Street.