Towards a causal effective thermodynamics of scalar-tensor gravity
General Relativity and Quantum Cosmology
2026-05-26 v1
Abstract
The thermal analogy between the effective fluid of scalar-tensor gravity and Eckart's irreversible thermodynamics is extended to the causal Israel-Stewart model, adopting the minimal ansatz of promoting the heat flux density to a timelike vector. This choice yields analytically manageable constitutive equations, allowing for the first consistent decoupling of the effective temperature and the effective thermal conductivity of scalar-tensor gravity. Crucially, this new framework preserves the interpretation of general relativity as the equilibrium state approached via a dynamical relaxation process in the vanishing- limit. This new causal formalism is applied to cosmology.
Keywords
Cite
@article{arxiv.2605.24133,
title = {Towards a causal effective thermodynamics of scalar-tensor gravity},
author = {Narayan Banerjee and Andrea Giusti and Valerio Faraoni and Luca Gallerani and Alain Maltais-Gosselin},
journal= {arXiv preprint arXiv:2605.24133},
year = {2026}
}