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arXiv · 2607.28209

Homogeneous and Isotropic Linearized Gravity as a Caldeira--Leggett System

Pelayo V. Calzada·Pedro Bargueño
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Abstract

We show that the homogeneous and isotropic sector of linearized gravity coupled to arbitrary additional degrees of freedom takes the Caldeira-Leggett form, provided their action contains no metric time derivatives at second order in perturbations. These additional degrees of freedom constitute the model's harmonic reservoir. Eliminating them yields a generalized Langevin equation for the metric perturbation, with their influence condensed in the reservoir's spectral density. This equivalence also yields a natural setting for reduced quantization of the perturbation and stochastic gravitational dynamics. We analyze the resulting dynamics with Laplace methods, extending results presented in other open-system settings.

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Pelayo V. Calzada, Pedro Bargueño. 2026-09-16. Homogeneous and Isotropic Linearized Gravity as a Caldeira--Leggett System. https://arxiv.org/abs/2607.28209

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