The research in our group is carried out in a variety of directions. Here you’ll find a brief description of the research we are currently engaged in.

Long-range correlations in driven systems

We study the properties of systems that driven out of equilibrium by an external field such as temperature gradient or electric field. This is an important class of nonequilibrium system, whose behavior is rather simple and resembles that of equilibrium systems. Because of their nonequilibrium nature there is now universal theory that explains  the steady-state properties of driven system. One way to study them is to compare their behavior with that of equilibrium systems. Driven systems tend exhibit long-range correlations, and their properties might therefore be related to those of equilibrium systems with long-range interactions.  The latter have recently been shown to exhibit unique phenomena that cannot be found in the more common short-range interacting systems. These include phase-transitions in one-dimension, slow relaxations, inequivalence of ensembles and others. We wish investigate similar phenomena in prototypical driven models. Our hope is to infer from our understanding of equilibrium systems with long-range interactions about the behavior of driven systems in general.

So far we have studied the phenomena of inequivalence of ensembles in a specific driven model, namely the ABC model [Evans1998]. The model is composed of three species of particles, denoted as A,B and C, hopping on a one-dimensional periodic lattice. The hopping rates are asymmetric, modeling the effect of an external field. As the strength of this asymmetry is increased the model undergoes a phase transition from a disordered to an ordered phase :

In order to observed inequivalence of ensembles we have introduced an additional inert species of particles, referred as vacancies. We have observed different behaviors in the case the number of vacancies was fixed are was allowed to fluctuate, similar to inequivalence of canonical and grand-canonical ensembles in equilibriun systems with long-range interactions. You may read more about it this research in Lederhendler2010a and Lederhendler2010b.

Systems with long-range interactions

Statistical properties of biomolecules

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