SIMULATION OF COSMOLOGICAL HORIZONS BY ULTRACOLD ATOMS IN OPTICAL LATTICES AND MULTI-JOSEPHSON-JUNCTION LOOPS

Excessive formation of topological defects (monopoles, vortices, and domain walls) between the subregions separated by cosmological horizons is a long-standing problem in treatment of the phase transitions in the early Universe. An important hint at its resolution was given in the last decade by the multi-Josephson-junction loop (MJJL) experiment and the experiments with ultracold atoms in optical potentials, which revealed the specific thermal correlations between the phases of order parameter in the spatial subregions disconnected in the course of the phase transition. It is shown in the present report that inclusion of such correlations into the simplest FRW cosmological model considerably reduces the number of the defects formed and, thereby, shows a promising way to resolve the long-standing cosmological puzzle.