i will recall a construction of certain operator algebras arising naturally as multiparameter deformations of  operator algebras of coxeter groups, initially motivated by the study of cohomology of groups acting on buildings. we will explain that for right-angled coxeter groups, at a certain range of multiparameters, the resulting von neumann algebra is a factor, thus completing earlier results of garncarek, and of caspers, klisse and larsen. this result, of interest in itself, has several consequences and interpretations for the representation theory of both right-angled coxeter groups and of certain groups acting on buildings. i will also outline further questions/results related to the classification of the related c*-algebras.

based on joint work with sven raum.