English

C*-envelopes of semicrossed products by lattice ordered abelian semigroups

Operator Algebras 2021-02-08 v2

Abstract

A semicrossed product is a non-selfadjoint operator algebra encoding the action of a semigroup on an operator or C*-algebra. We prove that, when the positive cone of a discrete lattice ordered abelian group acts on a C*-algebra, the C*-envelope of the associated semicrossed product is a full corner of a crossed product by the whole group. By constructing a C*-cover that itself is a full corner of a crossed product, and computing the Shilov ideal, we obtain an explicit description of the C*-envelope. This generalizes a result of Davidson, Fuller, and Kakariadis from Z+n\mathbb{Z}_+^n to the class of all discrete lattice ordered abelian groups.

Keywords

Cite

@article{arxiv.2001.07294,
  title  = {C*-envelopes of semicrossed products by lattice ordered abelian semigroups},
  author = {Adam Humeniuk},
  journal= {arXiv preprint arXiv:2001.07294},
  year   = {2021}
}

Comments

36 pages. Updated to reflect published version in JFA. Minor typos fixed throughout and new Corollary 3.18 (nonunital case) and Subsection 6.1 (simplicity of the C*-envelope) added