l2-Betti numbers of discrete and non-discrete groups

Abstract

This survey is an extended version of a talk during the Arbeitsgemeinschaft on totally disconnected locally compact groups, held in Oberwolfach in October 2014. We explain the definition of l2-Betti numbers of locally compact groups -- both discrete and non-discrete. Specific topics include proportionality principle, dimension function, Petersen's definition for locally compact groups, examples.

updated reference list; minor changes in section in QI section

References in corpus (1)

• Group approximation in Cayley topology and coarse geometry, Part III: Geometric property (T)

Cited by in corpus (2)

• $L^2$-Betti numbers of totally disconnected groups and their approximation by Betti numbers of lattices
• Finitely presented simple groups and measure equivalence