Actions affines isom\'etriques propres des groupes hyperboliques sur des   espaces $\ell^{p}$
  We give a simple and relatively short proof of the following fact: any hyperbolic group admits a proper affine isometric action on a $\ell^p$-space for $p$ large enough. A first proof of this result was given by Guoliang Yu. 
Aur\'elien Alvarez, Vincent Lafforgue
math.FA