Noncommutative boundaries and the ideal structure of reduced crossed products

  title={Noncommutative boundaries and the ideal structure of reduced crossed products},
  author={Matthew Kennedy and Christopher Schafhauser},
  journal={Duke Mathematical Journal},
A C*-dynamical system is said to have the ideal separation property if every ideal in the corresponding crossed product arises from an invariant ideal in the C*-algebra. In this paper we characterize this property for unital C*-dynamical systems over discrete groups. To every C*-dynamical system we associate a "twisted" partial C*-dynamical system that encodes much of the structure of the action. This system can often be "untwisted," for example when the algebra is commutative, or when the… 
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