Secondary Characteristic Classes and Cyclic Cohomology of Hopf Algebras
  We give a construction of cyclic cocycles representing the equivariant characteristic classes of equivariant bundles.   Our formulas generalize Connes' Godbillon-Vey cyclic cocycle. An essential tool of our construction is Connes-Moscovici's theory of cyclic cohomology of Hopf algebras. 
Alexander Gorokhovsky