English

Nearly approximate transitivity (AT) for circulant matrices

Dynamical Systems 2019-08-15 v1 Operator Algebras

Abstract

By previous work of Giordano and the author, ergodic actions of Z\Z (and other discrete groups) are completely classified measure-theoretically by their dimension space, a construction analogous to the dimension group used in C*-algebras and topological dynamics. Here we investigate how far from AT (approximately transitive) can actions be which derive from circulant (and related) matrices. It turns out not very: although non-AT actions can arise from this method of construction, under very modest additional conditions, ATness arises; in addition, if we drop the positivity requirement in the isomorphism of dimension spaces, then all these ergodic actions satisfy an analogue of AT. Many examples are provided

Keywords

Cite

@article{arxiv.1411.6301,
  title  = {Nearly approximate transitivity (AT) for circulant matrices},
  author = {David Handelman},
  journal= {arXiv preprint arXiv:1411.6301},
  year   = {2019}
}
R2 v1 2026-06-22T07:09:11.646Z