Construction of Spectral Triples Starting from Fredholm Modules

Abstract

Let (A,H,F) be a p-summable Fredholm module where the algebra A= C \Gamma is generated by a discrete group of unitaries in L(H) which is of polynomial growth r. Then we construct a spectral triple (A,H,D) with F= sign D which is q-summable for each q > p+r+1. In case (A,H,F) is (p,\infty)-summable we obtain (q,\infty)-summability of (A,H,D) for each q > p+r+1.