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arXiv · 1304.3502

Unitary equivalence of automorphisms of separable C*-algebras

Martino Lupini
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Abstract

We prove that the automorphisms of any separable C*-algebra that does not have continuous trace are not classifiable by countable structures up to unitary equivalence. This implies a dichotomy for the Borel complexity of the relation of unitary equivalence of automorphisms of a separable unital C*-algebra: Such relation is either smooth or not even classifiable by countable structures.

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Martino Lupini. 2013-04-11. Unitary equivalence of automorphisms of separable C*-algebras. https://doi.org/10.1016/j.aim.2014.05.022

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