English

Pure states on Cuntz algebras arising from geometric progressions

Operator Algebras 2016-01-29 v2

Abstract

Let On{\cal O}_n denote the Cuntz algebra for n2n\geq 2. We introduce an embedding ff of Om{\cal O}_m into On{\cal O}_n arising from a geometric progression of Cuntz generaters of On{\cal O}_n. By identifying Om{\cal O}_m with f(Om)f({\cal O}_m), we extend Cuntz states on Om{\cal O}_m to On{\cal O}_n. We show (i) a necessary and sufficient condition of the uniqueness of the extension, (ii) the complete classification of all such extensions up to unitary equivalence of their GNS representations, and (iii) the decomposition formula of a mixing state into a convex hull of pure states. The complete set of invariants of all GNS representations by such pure states is given as a certain set of complex unit vectors.

Keywords

Cite

@article{arxiv.1509.07581,
  title  = {Pure states on Cuntz algebras arising from geometric progressions},
  author = {Katsunori Kawamura},
  journal= {arXiv preprint arXiv:1509.07581},
  year   = {2016}
}

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35 pages