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Updated: Aug 9, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Nonequilibrium thermodynamics of spacetime
Christopher Eling1, Raf Guedens, Ted Jacobson
1Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA.
Physical Review Letters
|April 12, 2006
Summary
Einstein
Area of Science:
- Theoretical physics
- Gravitational thermodynamics
Background:
- The Einstein equation is derivable from the Clausius relation applied to local acceleration horizons.
- dS = deltaQ/T relates entropy change to energy flux and Unruh temperature.
Purpose of the Study:
- To investigate the implications of curvature corrections to entropy in gravitational thermodynamics.
- To derive the modified field equation incorporating these corrections.
Main Methods:
- Introducing a curvature correction to the entropy, polynomial in the Ricci scalar.
- Employing a nonequilibrium thermodynamic treatment for entropy balance.
- Determining the bulk viscosity entropy production term (diS) via energy-momentum conservation.
Main Results:
- Curvature corrections necessitate a nonequilibrium approach to entropy.
- A modified entropy balance relation dS = deltaQ/T + diS is established.
- The inclusion of shear viscosity in pure Einstein theory is shown to account for entropy production.
Conclusions:
- Modified entropy relations are crucial for incorporating curvature effects in gravity.
- Nonequilibrium thermodynamics provides a framework for understanding entropy production in gravitational contexts.
- Viscosity, both bulk and shear, plays a role in horizon thermodynamics.
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