Texas A&M University, Department of
Mathematics, 216 Milner Hall, 17th of October 2007, 3:00-3:50
Groups and Dynamics Seminar
Recent results on
the free lamplighter group and approximation properties, after Ozawa,
Popa,
Valette, et al.
Gilles Pisier of
Texas A&M
University
We present the Ozawa-Popa proof that the reduced C*-algebra of the
"free lamplighter" group fails the completely contractive AP
(Approximation Property) and the Valette et al. proof that it has the
Haagerup AP, thus answering negatively a question of Cowling.