#1 Limit theorems for Coulomb gases on a Jordan curve in an external potential [PDF] [Copy] [Kimi] [REL]
Authors: Kurt Johansson, Thomas Wolfs

We consider a Coulomb gas on a Jordan curve γ
in an external potential V
at inverse temperature β>0
and obtain an asymptotic expansion of the free energy up to o(1)
and a central limit theorem for linear statistics. We focus on the one-cut regime, where the density of the weighted equilibrium measure of γ
in V
is strictly positive on γ
. The constant term in the (normalized) expansion consists of two parts: the Fredholm determinant of a generalized Grunsky operator and the Dirichlet energy of the logarithm of the density of the weighted equilibrium measure of γ
. The coefficient of the latter vanishes for β=2
. The variance of the fluctuations of the linear statistics only depends on the Dirichlet energy of the test function and is therefore independent of V
. Essential in our approach is that the generalized Grunsky operator and the accompanying equilibrium parametrization allow us to transport the particles on the curve in the external potential to a reference object in a way that preserves the equilibrium measure. In our setting, the unit circle is the natural reference object.