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Construction of spectral triples starting from Fredholm modules. (Construction de triplets spectraux à partir de modules de Fredholm.) (French. Abridged English version) Zbl 0934.46062

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

MSC:

46L51 Noncommutative measure and integration
46L05 General theory of \(C^*\)-algebras