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arXiv · 2211.01392

Rényi Mutual Information in Quantum Field Theory

Jonah Kudler-Flam
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Abstract

We study a proper definition of Rényi mutual information (RMI) in quantum field theory as defined via the Petz Rényi relative entropy. Unlike the standard definition, the RMI we compute is a genuine measure of correlations between subsystems, as evidenced by its non-negativity and monotonicity under local operations. Furthermore, the RMI is UV finite and well-defined in the continuum limit. We develop a replica path integral approach for the RMI in quantum field theories and evaluate it explicitly in 1+1D conformal field theory using twist fields. We prove that it bounds connected correlation functions and check our results against exact numerics in the massless free fermion theory.

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BibTeXRIS

Jonah Kudler-Flam. 2023-01-13. Rényi Mutual Information in Quantum Field Theory. https://doi.org/10.1103/physrevlett.130.021603

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