Group Quasi-representations and Index Theory
نویسنده
چکیده
Let M be a closed connected manifold and let D be an elliptic operator on M . Let G be a discrete countable group and let M̃ → M be a principal G-bundle. Connes and Moscovici showed that this data defines an analytic index ind`1(G)(D) ∈ K0(`(G)). If B is a unital tracial C*-algebra, we give a formula for the trace of the image of ind`1(G)(D) in K0(B) under the map induced by a quasi-representation of G in B. As an application, we reprove and generalize a formula of Exel and Loring to surface groups.
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