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Relative entropy for λϕ4 in the Rindler wedge

Markus B. Fröb1, Albert Much2,3, and Kyriakos Papadopoulos4,*

  • *Contact author: kyriakos.papadopoulos@ku.edu.kw
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Phys. Rev. D 114, 085001 – Published 1 October, 2026

DOI: https://doi.org/10.1103/z7jp-p1xx

Abstract

We consider the relative entropy between the vacuum and a coherent state in the Rindler wedge for an interacting λϕ4 theory to first order in λ. We construct the perturbatively interacting Weyl algebra of the wedge, and employ Tomita-Takesaki modular theory and the Araki-Uhlmann formula to compute the relative entropy. We verify that the relative entropy reduces to the classical (interacting) boost Noether charge, analogously to the free theory, and that the Bekenstein bound holds.

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Phys. Rev. D 114, 085001– Published 1 October, 2026
  • Received 30 March 2026
  • Accepted 10 September 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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