English

Morita Equivalence and Spectral Triples on Noncommutative Orbifolds

Differential Geometry 2016-06-22 v1 Mathematical Physics math.MP Operator Algebras

Abstract

Let GG be a finite group. Noncommutative geometry of unital GG-algebras is studied. A geometric structure is determined by a spectral triple on the crossed product algebra associated with the group action. This structure is to be viewed as a representative of a noncommutative orbifold. Based on a study of classical orbifold groupoids, a Morita equivalence for the crossed product spectral triples is developed. Noncommutative orbifolds are Morita equivalence classes of the crossed product spectral triples. As a special case of this Morita theory one can study freeness of the GG-action on the noncommutative level. In the case of a free action, the crossed product formalism reduced to the usual spectral triple formalism on the algebra of GG-invariant functions.

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Cite

@article{arxiv.1504.04729,
  title  = {Morita Equivalence and Spectral Triples on Noncommutative Orbifolds},
  author = {Antti J. Harju},
  journal= {arXiv preprint arXiv:1504.04729},
  year   = {2016}
}