Are there Thermodynamical Degrees of Freedom of Gravitation?

TL;DR

This paper examines whether gravitation possesses thermodynamical degrees of freedom, concluding that standard general-relativistic thermodynamics does not assign such degrees to gravity, but alternative approaches suggest possible exceptions.

Contribution

It reviews and contrasts different theoretical perspectives on the thermodynamical nature of gravitation, highlighting the debate on whether gravity has thermodynamical degrees of freedom.

Findings

Standard general-relativistic thermodynamics lacks gravitational degrees of freedom.

Black hole thermodynamics challenges the harmlessness of gravity.

Alternative approaches propose possible thermodynamical aspects of gravity.

Abstract

In discussing fundamentals of general-relativistic irreversible continuum thermodynamics, this theory is shown to be characterized by the feature that no thermodynamical degrees of freedom are ascribed to gravitation. However, accepting that black hole thermodynamics seems to oppose this harmlessness of gravitation one is called on consider other approaches. Therefore, in brief some gravitational and thermodynamical alternatives are reviewed.