On the Local Equilibrium Principle
Abstract
Description
A physical system should be in a local equilibrium if it cannot be distinguished from a global equilibrium by ``infinitesimally localized measurements''. This seems to be a natural characterization of local equilibrium, however the problem is to give a precise meaning to the qualitative phrase ``infinitesimally localized measurements''.
A solution is suggested in form of a {\em Local Equilibrium Condition} (LEC) which can be applied to non-interacting quanta.
The Unruh temperature of massless quanta is derived by applying LEC to an arbitrary point inside the Rindler Wedge.
Massless quanta outside a hot sphere are analyzed. A stationary spherically symmetric local equilibrium does only exist according to LEC if the temperature is globally constant.
Using LEC a non-trivial stationary local equilibrium is found for rotating massless quanta between two concentric cylinders of different temperatures. This shows that quanta may behave like a fluid with a Bénard instability.
21 pages (LaTeX). An argument has been slightly improved with no effect on the conclusions
21 pages (LaTeX). An argument has been slightly improved with no effect on the conclusions