English

Moves on $k$-graphs preserving Morita equivalence

Operator Algebras 2020-06-25 v1

Abstract

We initiate the program of extending to higher-rank graphs (kk-graphs) the geometric classification of directed graph CC^*-algebras, as completed in the 2016 paper of Eilers, Restorff, Ruiz, and Sorensen [ERRS16]. To be precise, we identify four "moves," or modifications, one can perform on a kk-graph Λ\Lambda, which leave invariant the Morita equivalence class of its CC^*-algebra C(Λ)C^*(\Lambda). These moves -- insplitting, delay, sink deletion, and reduction -- are inspired by the moves for directed graphs described by Sorensen [S\o13] and Bates-Pask [BP04]. Because of this, our perspective on kk-graphs focuses on the underlying directed graph. We consequently include two new results, Theorem 2.3 and Lemma 2.9, about the relationship between a kk-graph and its underlying directed graph.

Keywords

Cite

@article{arxiv.2006.13441,
  title  = {Moves on $k$-graphs preserving Morita equivalence},
  author = {Caleb Eckhardt and Kit Fieldhouse and Daniel Gent and Elizabeth Gillaspy and Ian Gonzales and David Pask},
  journal= {arXiv preprint arXiv:2006.13441},
  year   = {2020}
}