Weak amenability for dynamical systems
Volume 258 / 2021
Studia Mathematica 258 (2021), 53-70
MSC: Primary 46L55; Secondary 46L05.
DOI: 10.4064/sm200227-20-7
Published online: 15 October 2020
Abstract
Using the recently developed notion of a Herz–Schur multiplier of a $C^*$-dynamical system we introduce weak amenability of $C^*$- and $W^*$-dynamical systems. As a special case we recover Haagerup’s characterisation of weak amenability of a discrete group. We also consider a generalisation of the Fourier algebra and its multipliers to crossed products.
