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  • Open Access

Nonequilibrium thermodynamics of gravitational objective-collapse models

Simone Artini1, Gabriele Lo Monaco1, Sandro Donadi2,3, and Mauro Paternostro1,2,*

  • *Contact author: mauro.paternostro@unipa.it
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Phys. Rev. Research 7, 043017 – Published 3 October, 2025

DOI: https://doi.org/10.1103/7hqd-zf96

Abstract

We investigate the entropy production in the Diósi-Penrose (DP) model, one of the most extensively studied gravity-related collapse mechanisms, and one of its dissipative extensions. To this end, we analyze the behavior of a single harmonic oscillator, subjected to such collapse mechanisms, focusing on its phase-space dynamics and the time evolution of the entropy production rate—a central quantity in nonequilibrium thermodynamics. Our findings reveal that the original DP model induces unbounded heating, producing dynamics consistent with the second law of thermodynamics only under the assumption of an infinite-temperature noise field. In contrast, its dissipative extension achieves physically consistent thermalization in the regime of low dissipation strength. Using a short-time approach, we further our study to address the complete dynamics of the dissipative extension, thus including explicitly non-Gaussian features in the state of the system that lack from the low-dissipation regime.

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Phys. Rev. Research 7, 043017– Published 3 October, 2025
  • Received 18 February 2025
  • Accepted 23 July 2025
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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.

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