抄録< jats: p> Property (T) is a rigidity property for topological groups, first formulated by D.
Kazhdan in the mid 1960's with the aim of demonstrating that a large class of lattices are …

The key idea in geometric group theory is to study infinite groups by endowing them with a
metric and treating them as geometric spaces. This applies to many groups naturally …

We present an example of a generalized Brownian motion. It is given by creation and
annihilation operators on a “twisted” Fock space of L 2 (ℝ). These operators fulfill (for a …

A locally compact group has the Haagerup property, or is aT-menable in the sense of
Gromov, if it admits a proper isometric action on some affine Hilbert space. As Gromov's pun …

In this article we prove that quasi-multiplicative (with respect to the usual length function)
mappings on the permutation group $\SSn $(or, more generally, on arbitrary amenable …

We present an update of Garland's work on the cohomology of certain groups, construct a
class of groups many of which satisfy Kazhdan's Property (T) and show that properly …

We show that groups satisfying Kazhdan's property (T) have no unbounded actions on finite
dimensional CAT (0) cube complexes, and deduce that there is a locally CAT (− 1) …

I. Introduction. Throughout the last two or three decades, the theory of rigidity, particularly in
relation to semisimple groups and their discrete subgroups, has become an extremely active …

We prove the existence of a close connection between spaces with measured walls and
median metric spaces. We then relate properties (T) and Haagerup (aT-menability) to …

A hyperbolic reflection group is a discrete group generated by reflections in the faces of an $
n $-dimensional hyperbolic polyhedron. This survey article is dedicated to the study of …