Phase Transitions in the Early Universe

Abstract

The physics of the 20th Century is governed by two pillars, Einstein's relativity principle and the quantum principle. At the beginning of the 21st Century, it becomes clear that there exist the smallest units of matter, such as electrons, neutrinos, and quarks; their behaviors are described by the Standard Model. It was believed that the temperature of the early Universe was once 300 GeV, or higher, at $10^{-11} sec$, and then going through the electroweak phase transition. But the mass phase transition happens in the purely imaginary temperature. Later on, its temperature was 150 MeV at $3.3 \times 10^{-5} sec$, and then going through the "QCD cosmological phase transition". We attempt to use the Standard Model, a completely dimensionless theory apart from the negative "ignition" term, to conclude that the EW or mass phase transition {\it does not exist}. On the front of QCD cosmological phase transition, the intriguing question about the latent heat (energy) is discussed and its role is speculated.