English

Universal covering space of the noncommutative torus

Operator Algebras 2014-01-28 v1

Abstract

Gelfand - Na\u{i}mark theorem supplies contravariant functor from a category of commutative CC^*- algebras to a category of locally compact Hausdorff spaces. Therefore any commutative CC^*- algebra is an alternative representation of a topological space. Similarly a category of (noncommutative) CC^*- algebras can be regarded as a category of generalized (noncommutative) locally compact Hausdorff spaces. Generalizations of topological invariants may be defined by algebraic methods. For example Serre Swan theorem states that complex topological KK - theory coincides with KK - theory of CC^* - algebras. However the algebraic topology have a rich set of invariants. Some invariants do not have noncommutative generalizations yet. This article contains a sample of noncommutative universal covering. General theory of noncommutative universal coverings is being developed by the author of this article. However this sample has independent interest, it is very easy to understand and does not require knowledge of Hopf-Galois extensions.

Keywords

Cite

@article{arxiv.1401.6748,
  title  = {Universal covering space of the noncommutative torus},
  author = {Petr R. Ivankov},
  journal= {arXiv preprint arXiv:1401.6748},
  year   = {2014}
}

Comments

7 pages