English

Spectral triples and finite summability on Cuntz-Krieger algebras

K-Theory and Homology 2015-03-02 v3 Functional Analysis Operator Algebras Quantum Algebra

Abstract

We produce a variety of odd bounded Fredholm modules and odd spectral triples on Cuntz-Krieger algebras by means of realizing these algebras as "the algebra of functions on a non-commutative space" coming from a sub shift of finite type. We show that any odd KK-homology class can be represented by such an odd bounded Fredholm module or odd spectral triple. The odd bounded Fredholm modules that are constructed are finitely summable. The spectral triples are θ\theta-summable although their bounded transform, when constructed using the sign-function, will already on the level of analytic KK-cycles be finitely summable bounded Fredholm modules. Using the unbounded Kasparov product, we exhibit a family of generalized spectral triples, possessing mildly unbounded commutators, whilst still giving well defined KK-homology classes.

Keywords

Cite

@article{arxiv.1401.2123,
  title  = {Spectral triples and finite summability on Cuntz-Krieger algebras},
  author = {Magnus Goffeng and Bram Mesland},
  journal= {arXiv preprint arXiv:1401.2123},
  year   = {2015}
}

Comments

67 pages, minor changes in Section 5.1 and 6.1