Applying Jacobson's thermodynamic derivation to general non-Riemannian spacetimes selects a unique Einstein-Hilbert-plus-torsion-vector-squared theory in the torsion-only case, and yields no action-based theory when non-metricity is present.
Higher derivative gravity: field equation as the equation of state
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
One of the striking features of general relativity is that the Einstein equation is implied by the Clausius relation imposed on a small patch of locally constructed causal horizon. Extension of this thermodynamic derivation of the field equation to more general theories of gravity has been attempted many times in the last two decades. In particular, equations of motion for minimally coupled higher curvature theories of gravity, but without the derivatives of curvature, have previously been derived using a thermodynamic reasoning. In that derivation the horizon slices were endowed with an entropy density whose form resembles that of the Noether charge for diffeomorphisms, and was dubbed the Noetheresque entropy. In this paper, we propose a new entropy density, closely related to the Noetheresque form, such that the field equation of any diffeomorphism invariant metric theory of gravity can be derived by imposing the Clausius relation on a small patch of local causal horizon.
representative citing papers
Derives semi-classical gravity from thermodynamics of stretched light cones in 2D dilaton gravity with explicit conformal anomaly backreaction and shows equations of motion follow from dynamical Wald entropy in Brans-Dicke theories.
citing papers explorer
-
Jacobson's thermodynamic approach to classical gravity applied to non-Riemannian geometries: remarks on the simplicity of Nature
Applying Jacobson's thermodynamic derivation to general non-Riemannian spacetimes selects a unique Einstein-Hilbert-plus-torsion-vector-squared theory in the torsion-only case, and yields no action-based theory when non-metricity is present.
-
Semi-classical spacetime thermodynamics
Derives semi-classical gravity from thermodynamics of stretched light cones in 2D dilaton gravity with explicit conformal anomaly backreaction and shows equations of motion follow from dynamical Wald entropy in Brans-Dicke theories.