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arXiv · 1302.0426

Ergodic Actions and Spectral Triples

Olivier Gabriel·Martin Grensing
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Abstract

In this article, we give a general construction of spectral triples from certain Lie group actions on unital C*-algebras. If the group G is compact and the action is ergodic, we actually obtain a real and finitely summable spectral triple which satisfies the first order condition of Connes' axioms. This provides a link between the "algebraic" existence of ergodic action and the "analytic" finite summability property of the unbounded selfadjoint operator. More generally, for compact G we carefully establish that our (symmetric) unbounded operator is essentially selfadjoint. Our results are illustrated by a host of examples - including noncommutative tori and quantum Heisenberg manifolds.

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Olivier Gabriel, Martin Grensing. 2013-02-02. Ergodic Actions and Spectral Triples. https://arxiv.org/abs/1302.0426

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