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arXiv · 2203.14934

Stealth metastable state of scalar-tensor thermodynamics

Valerio Faraoni·Théo B. Françonnet
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Abstract

We investigate a puzzle in the recent thermodynamics of scalar-tensor gravity, in which general relativity is a zero-temperature state of equilibrium and scalar-tensor gravity is the non-equilibrium configuration of an effective dissipative fluid. A stealth solution of Brans-Dicke gravity with constant positive temperature is shown to be analogous to a metastable state for the effective fluid and to suffer from an instability. The stability analysis employs a version of the Bardeen-Ellis-Bruni-Hwang gauge-invariant formalism for cosmological perturbations adapted to modified gravity. The metastable state is destroyed by tensor perturbations.

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Valerio Faraoni, Théo B. Françonnet. 2022-03-28. Stealth metastable state of scalar-tensor thermodynamics. https://doi.org/10.1103/physrevd.105.104006

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