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Symmetries of Decoherence Functionals

S. Schreckenberg
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Abstract

The basic ingredients of the `consistent histories' approach to quantum theory are a space $\UP$ of `history propositions' and a space $\D$ of `decoherence functionals'. In this article we consider such history quantum theories in the case where $\UP$ is given by the set of projectors $¶(\V)$ on some Hilbert space $\V$. Using an analogue of Wigner's Theorem in the context of history quantum theories proven earlier, we develop the notion of a `symmetry of a decoherence functional' and prove that all such symmetries form a group which we call `the symmetry group of a decoherence functional'. We calculate---for the case of history quantum mechanics---some of these symmetries explicitly and relate them to some discussions that have appeared previously.

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S. Schreckenberg. 1996-07-23. Symmetries of Decoherence Functionals. https://doi.org/10.1063/1.531889

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