English

$K$-stability of $C^*$-algebras generated by isometries and unitaries with twisted commutation relations

Operator Algebras 2025-06-16 v2 K-Theory and Homology

Abstract

In this article, we prove KK-stability for a family of CC^*-algebras, which are generated by a finite set of unitaries and isometries satisfying twisted commutation relations. This family includes the CC^*-algebra of doubly non-commuting isometries and free twist of isometries. Next, we consider the CC^*-algebra AVA_{\mathcal{V}} generated by an nn-tuple of U\mathcal{U}-twisted isometries V\mathcal{V} with respect to a fixed (n2)n\choose 2-tuple U={Uij:1i<jn}\mathcal{U}=\{U_{ij}:1\leq i<j \leq n\} of commuting unitaries (see \cite{NarJaySur-2022aa}). Under the assumption that the spectrum of the commutative CC^*-algebra generated by ({Uij:1i<jn})(\{U_{ij}:1\leq i<j \leq n\}) does not contain any element of finite order in the torus group \bbbt(n2)\bbbt^{n\choose 2}, we show that AVA_{\mathcal{V}} is KK-stable. Finally, we prove the same result for the CC^*-algebra generated by a tuple of free U\mathcal{U}-twisted isometries.

Keywords

Cite

@article{arxiv.2312.06189,
  title  = {$K$-stability of $C^*$-algebras generated by isometries and unitaries with twisted commutation relations},
  author = {Shreema Subhash Bhatt and Bipul Saurabh},
  journal= {arXiv preprint arXiv:2312.06189},
  year   = {2025}
}

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