Emergence of macroscopic temperatures in systems that are not thermodynamical microscopically: towards a thermodynamical description of slow granularrheology
J. Kurchan, Emergence of macroscopic temperatures in systems that are not thermodynamical microscopically: towards a thermodynamical description of slow granularrheology, J PHYS-COND, 12(29), 2000, pp. 6611-6617
A scenario for systems with slow dynamics is characterized by stating that
there are several temperatures coexisting for the sample, with a single tem
perature shared by all observables at each (widely separate) timescale.
In preparation for the study of granular rheology, we show within this fram
ework that glassy systems with driving and friction that are generic and do
not correspond to a thermal bath-and whose microscopic 'fast' motion is he
nce not thermal-have a well-defined macroscopic temperature associated with
the slow degrees of freedom.
This temperature is what a thermometer coupled to the system will measure i
f tuned to respond to low frequencies, and, since it can be related to the
number of stationary configurations, it is the formalization of Edwards' 'c
ompactivity' ideas.