The spectral localizer for semifinite spectral triples

Schulz-Baldes, Hermann; Stoiber, Tom

doi:10.1090/proc/15230

The spectral localizer for semifinite spectral triples
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by Hermann Schulz-Baldes and Tom Stoiber PDF

Proc. Amer. Math. Soc. 149 (2021), 121-134 Request permission

Abstract:

The notion of a spectral localizer is extended to pairings with semifinite spectral triples. By a spectral flow argument, any semifinite index pairing is shown to be equal to the signature of the spectral localizer. As an application, a formula for the weak invariants of topological insulators is derived. This provides a new approach to their numerical evaluation.

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