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arXiv · 2310.06691

Freedman's theorem for unitarily invariant states on the CCR algebra

Vitonofrio Crismale·Simone Del Vecchio·Tommaso Monni·Stefano Rossi
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Abstract

The set of states on ${\rm CCR}(\ch)$, the CCR algebra of a separable Hilbert space $\ch$, is here looked at as a natural object to obtain a non-commutative version of Freedman's theorem for unitarily invariant stochastic processes. In this regard, we provide a complete description of the compact convex set of states of ${\rm CCR}(\ch)$ that are invariant under the action of all automorphisms induced in second quantization by unitaries of $\ch$. We prove that this set is a Bauer simplex, whose extreme states are either the canonical trace of the CCR algebra or Gaussian states with variance at least $1$.

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Vitonofrio Crismale, Simone Del Vecchio, Tommaso Monni, Stefano Rossi. 2023-10-10. Freedman's theorem for unitarily invariant states on the CCR algebra. https://arxiv.org/abs/2310.06691

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