E. Caglioti et al., A SPECIAL-CLASS OF STATIONARY FLOWS FOR 2-DIMENSIONAL EULER EQUATIONS- A STATISTICAL-MECHANICS DESCRIPTION .2., Communications in Mathematical Physics, 174(2), 1995, pp. 229-260
We continue and conclude our analysis started in Part I (see [CLMP]) b
y discussing the microcanonical Gibbs measure associated to a N-vortex
system in a bounded domain. We investigate the Mean-Field limit for s
uch a system and study the corresponding Microcanonnical Variational P
rinciple for the Mean-Field equation. We discuss and achieve the equiv
alence of the ensembles for domains in which we have the concentration
at beta --> (-8 pi)(+) in the canonical framework. In this case we ha
ve the uniqueness of the solutions of the Mean-Field equation. For the
other kind of domains, for large values of the energy, there is no eq
uivalence, the entropy is not a concave function of the energy, and th
e Mean-field equation has more than one solution. In both situations,
we have concentration when the energy diverges. The Microcanonical Mea
n Field Limit for the N-vortex system is proven in the case of equival
ence of ensembles.