PHASE TRANSITIONS IN EARLY UNIVERSE
Taras Shevchenko National University of KyivAccording to the Big Bang theory, the early Universe was an extremely hot and dense environment. With time, the universe went through an inflationary period, causing a decrease in temperature. In statistical physics, systems that come from a high temperature state tending toward a low temperature state experience a symmetry breaking phase transition. This concept might be applied to model the evolution of the Universe. It is well known, that electromagnetic interaction described by U(1) symmetry and weak interaction SU(2) can be generalized into one electroweak interaction SU(2)*U(1) at high energies (temperatures). Division of these two interactions occurred earlier in the Universe, causing symmetry to break.