Casimir forces between inclusions in an out of equilibrium fluid

Abstract

At present time, the nature of the forces in out-equilibrium systems is still far to be well understood. It is hought that fuctuations appearing in these systems can play a crucial role. In the present report, we develop a computational model to systematically analyze the nature of interactions arising in an out-equilibrium system, consisting in two phosphor-bronze spheres surrounded by a bath of poppy seeds, subjected to an oscillatory forcing along one dimension. An experimental study of this system has been recently carried out in Universidad de Navarra and their results are not well explained yet. Here we show an important anisotropy in strength, the existence of short-range depletion forces and long-range attractive Casimir-like forces