## Coupling and thermal equilibrium in general-covariant systems

G. Chirco, H. M. Haggard, and C. Rovelli

*Physical Review D* **88** (084027), 2013.

A fully general-covariant formulation of statistical mechanics is still lacking. We take a step toward this theory by studying the meaning of statistical equilibrium for coupled, parametrized systems. We discuss how to couple parametrized systems. We express the thermalization hypothesis in a general-covariant context. This takes the form of vanishing of information flux. An interesting relation emerges between thermal equilibrium and gauge.

DOI: 10.1103/PhysRevD.88.084027

Full text: ChHaRoGeneralCovariantCoupling.pdf