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  • Open Access

Entanglement on a sphere

Konstantinos Boutivas*, Dimitrios Katsinis†, Georgios Pastras‡,¶, Nikolaos Prountzos§, and Nikolaos Tetradis∥

  • *Contact author: kboutivas@phys.uoa.gr
  • †Contact author: dkatsinis@phys.uoa.gr
  • ‡Contact author: pastras@lms.mech.upatras.gr
  • §Contact author: nproun@phys.uoa.gr
  • ∥Contact author: ntetrad@phys.uoa.gr
  • Also at Laboratory for Manufacturing Systems and Automation, Department of Mechanical Engineering and Aeronautics, University of Patras, 26110 Patra, Greece.
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Phys. Rev. D 112, 065020 – Published 25 September, 2025

DOI: https://doi.org/10.1103/8h9z-gmnm

Abstract

We study the entanglement entropy of a massive scalar field in the background of the Einstein universe. We determine numerically the structure of the UV-divergent terms. We study analytically the IR term that originates in the long-range correlations arising from the field zero mode on the sphere. We compare with previous results for a scalar field in a de Sitter or an anti–de Sitter background.

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Phys. Rev. D 112, 065020– Published 25 September, 2025
  • Received 16 July 2025
  • Accepted 9 September 2025
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