English

A note on non-unital absorbing extensions

Operator Algebras 2016-09-07 v2

Abstract

Elliott and Kucerovsky stated that a non-unital extension of separable CC^\ast-algebras with a stable ideal, is nuclearly absorbing if and only if the extension is purely large. However, their proof was flawed. We give a counter example to their theorem as stated, but establish an equivalent formulation of nuclear absorption under a very mild additional assumption to being purely large. In particular, if the quotient algebra is non-unital, then we show that the original theorem applies. We also examine how this effects results in classification theory.

Keywords

Cite

@article{arxiv.1408.4033,
  title  = {A note on non-unital absorbing extensions},
  author = {James Gabe},
  journal= {arXiv preprint arXiv:1408.4033},
  year   = {2016}
}

Comments

8 pages. Version II: Made minor changes and added a section with the counter example of Ruiz

R2 v1 2026-06-22T05:32:12.401Z