Cyclic cohomology of étale groupoids; The general case

Abstract

We give a general method for computing the cyclic cohomology of crossed products by etale groupoids extending the FeiginTsyganNistor spectral sequences In particular we extend the computations performed by Brylinski Burghelea Connes Feigin Karoubi Nistor and Tsygan for the convolution algebra C c G of an etale groupoid removing the Hausdorness condition and including the computation of hyperbolic components Examples like group actions on manifolds and foliations are considered