La propriete de decroissance rapide pour le groupe de Wise
  We show that the group of presentation $< a,b,c,s,t\mid c=ab=ba,\, c^2=sas^{-1}=tbt^{-1}>$ (introduced by D. Wise) has the property of rapid decay. 
Sylvain Barre and Mikael Pichot
math.GR