Incomplete equilibrium in long-range interacting systems.

Strange scaling and relaxation of finite-size fluctuation in thermal equilibrium.

We numerically exhibit two strange phenomena of finite-size fluctuation in thermal equilibrium of a paradigmatic long-range interacting system having a second-order phase transition. One is a nonclassical finite-size scaling at the critical point, which differs from the prediction by statistical mechanics. With the aid of this strange scaling, the scaling theory for infinite-range models conjec...

Energy landscapes, equilibrium and out of equilibrium physics of long and short range interacting systems

Kinetic theory for non-equilibrium stationary states in long-range interacting systems

We study long-range interacting systems perturbed by external stochastic forces. Unlike the case of short-range systems, where stochastic forces usually act locally on each particle, here we consider perturbations by external stochastic fields. The system reaches stationary states where external forces balance dissipation on average. These states do not respect detailed balance and support non-...

Surprises from quenches in long-range-interacting systems: temperature inversion and cooling

What happenswhen one of the parameters governing the dynamics of a long-range interacting system of particles in thermal equilibrium is abruptly changed (quenched) to a different value?While a shortrange system, under the same conditions, will relax in time to a new thermal equilibriumwith a uniform temperature across the system, a long-range system shows a fast relaxation to a nonequilibrium q...

Violent relaxation in two-dimensional flows with varying interaction range.

Understanding the relaxation of a system towards equilibrium is a long-standing problem in statistical mechanics. Here we address the role of long-range interactions in this process by considering a class of two-dimensional flows where the interaction between fluid particles varies with the distance as ∼r(α-2) for α>0. We find that changing α with a prescribed initial state leads to different f...