Phase transitions in the early and the present Universe: from the big bang to heavy ion collisions

Abstract

In these lectures I discuss cosmological phase transitions with the goal of establishing the possibility of observational consequences. I argue that the only phase transition amenable of experimental study within the foreseeable future is that predicted by QCD and discuss some of the potential observational cosmological consequences associated with this phase transition(s). I describe the experimental effort to study the QCD phase transition(s) at RHIC and SPS and summarize some of the recent experimental results. The possibility of novel phases of QCD in the core of pulsars is discussed along with the suggested observational consequences. A brief review of standard big bang cosmology as well as the astrophysics of compact stars sets the stage for understanding the observational cosmological and astrophysical consequences of phase transitions in the standard model.

Nonequilibrium quantum anharmonic oscillator and scalar field: high temperature approximations

“…The motivations for EDR explained previously also hold for NEDR. In heavy-ion collisions, large numbers of pions are produced and an important issue is how thermal equilibrium is created [21,22]. For some time interval, those pions can be regarded, as least approximately, as a nonequilibrium interacting relativistic quantum boson gas.…”