A new look at the Julg-Valette homotopy for groups acting on trees.

Pierre Julg (1)

1 MAPMO - Mathématiques - Analyse, Probabilités, Modélisation - Orléans

We propose a new look at the Julg-Valette theorem on K-theoretic amenability for groups operating on trees. The main tool is a generalization of a construction of uniformly bounded representations of the free groups due to Pytlik and Szwarc.

Mots clés: groups acting on trees; uniformly bounded representations

Domaines: Théorie des groupes [math.GR]; Algèbres d'opérateurs [math.OA]; Théorie des représentations [math.RT]; K-théorie et homologie [math.KT]

Pierre Julg. A new look at the Julg-Valette homotopy for groups acting on trees.. 2013. ⟨hal-00876928v1⟩