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Positive extensions of automorphisms of spin factors

Published online by Cambridge University Press:  14 November 2011

A. Guyan Robertson
Affiliation:
Department of Mathematics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ

Synopsis

A spin factor is a JW-factor of type I2. It is shown that certain automorphisms of finite dimensional spin factors extend to extremal positive linear maps on complex matrix algebras which are not decomposable, and hence, do not preserve extreme rays of the positive cone.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1983

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