On Losik Classes of Diffeomorphism Pseudogroups
摘要
Let P be a pseudogroup of local diffeomorphisms of an n-dimensional smooth manifold M. Following Losik we consider characteristic classes of the quotient M/P as elements of the de Rham cohomology of the second order frame bundles over M/P coming from the generators of the Gelfand-Fuchs cohomology. We provide explicit expressions for the classes that we call Godbillon-Vey-Losik class and the first Chern-Losik class. Reducing the frame bundles we construct bundles over M/P such that the Godbillon-Vey-Losik class is represented by a volume form on a space of dimension