English

The Automorphism group of a simple tracially AI algebra

Operator Algebras 2009-11-13 v1

Abstract

The structure of the automorphism group of a simple TAI algebra is studied. In particular, we show that \mrmInnˉ(A)\mrmInnˉ0(A)\frac{\bar{\mrm{Inn}} (A)}{\bar{\mrm{Inn}}_{0} (A)} is isomorphic (as a topological group) to an inverse limit of discrete abelian groups for a unital, simple, AH algebra with bounded dimension growth. Consequently, \mrmInnˉ(A)\mrmInnˉ0(A)\frac{\bar{\mrm{Inn}} (A)}{\bar{\mrm{Inn}}_{0} (A)} is totally disconnected. Another consequence of our results is the following: Suppose AA is the transformation group \cstar-algebra of a minimal Furstenberg transformation (\mbbTn,hn)(\mbb{T}^{n}, h_{n}) with a unique hnh_{n}-invariant probability measure on \mbbTn\mbb{T}^{n}. Then the automorphism group of AA is an extension of a simple topological group by the discrete group \mrmAut(\totalk(A))+,1\mrm{Aut} (\totalk(A))_{+,1}.

Keywords

Cite

@article{arxiv.math/0703674,
  title  = {The Automorphism group of a simple tracially AI algebra},
  author = {P. W. Ng and E. Ruiz},
  journal= {arXiv preprint arXiv:math/0703674},
  year   = {2009}
}

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35 pages