%0 Journal Article
%T Examples of groups which are not weakly amenable
%A Narutaka Ozawa
%J Mathematics
%D 2010
%I arXiv
%R 10.1215/21562261-1550985
%X We prove that weak amenability of a locally compact group imposes a strong condition on its amenable closed normal subgroups. This extends non weak amenability results of Haagerup (1988) and Ozawa--Popa (2010). A von Neumann algebra analogue is also obtained.
%U http://arxiv.org/abs/1012.0613v2