Protection of Metals and Physical Chemistry of Surfaces.
Maik Nauka Publishing / Springer SBM.
Vol. 46.
2010.
P. 202-205
We consider noncommutative elliptic operators over C*-algebras, associated with a discrete group of isometrics of a manifold. The main result of the paper is a formula expressing the Chern characters of the index (Connes invariants) in topological terms. As a corollary to this formula a simple proof of higher index formulae for noncommutative elliptic operators is obtained.