Quantum differentials of Spectral triples, Dirichlet spaces and discrete groups
Résumé
We study natural conditions on essentially discrete spectral triples by which the quantum differential da belongs to the ideal generated by the unit length ds=D−1. We also study upper and lower bounds on the singular values of the da's and apply the general framework to natural spectral triples of Dirichlet spaces and, in particular, those on dual of discrete groups arising from negative definite functions.