# Volkmar Welker: The Garland Method revisited

(ongoing work with Eric Babson)

**Time: **
Mon 2020-05-18 15.30

**Location: **
Zoom, registration required

**Participating: **
Volkmar Welker, Philipps-Universität Marburg

### Abstract

In the early 1970s Garland introduced a method to deduce the vanishing of homology groups of simplicial complexes with real coefficients through estimates on the smallest non-zero Eigenvalue of the "upper" Laplacian of the chain complexes of links. Later the method was refined and made more explicit in work of Zuk and Ballmann & Swiatkowski.

In this talk I present a conceptual version of the method phrased in the language of homological algebra. I demonstrate how the original "Garland method" fits this setting and exhibit further applications.

### Registration

If you haven't received a link before, please email smirnov@math.su.se .