Abstract:

A simplicial complex X will be called an excellent local spectral expander if the one-skeletons of all the links of X have excellent spectral gaps (including the one skeleton of X itself). This property is desirable because it leads to several global expansion phenomena. The aim of my talk is to present an elementary construction of excellent local spectral high dimensional expanders (the construction is elementary in the sense that describing it requires only basic matrix theory). This construction has another nice feature – it yields complexes that have large symmetry groups. This talk is based on a joint work with Tali Kaufman.

A simplicial complex X will be called an excellent local spectral expander if the one-skeletons of all the links of X have excellent spectral gaps (including the one skeleton of X itself). This property is desirable because it leads to several global expansion phenomena. The aim of my talk is to present an elementary construction of excellent local spectral high dimensional expanders (the construction is elementary in the sense that describing it requires only basic matrix theory). This construction has another nice feature – it yields complexes that have large symmetry groups. This talk is based on a joint work with Tali Kaufman.

## Date:

Mon, 11/12/2017 - 14:00 to 16:00

## Location:

Eilat Hall, Feldman Building (IIAS), Givat Ram