Based on the provided sources, here is a brief explanation of cosmological phase transitions and their significance in the early universe:

The Cooling Universe and Phase Transitions Shortly after the Big Bang, the universe was an incredibly hot, dense plasma. As space expanded and cooled, matter and fundamental forces underwent a series of cosmological phase transitions. Much like liquid water freezing into solid ice, the universe transitioned from highly symmetric, high-energy states into more ordered, lower-energy states. Key milestones include the Grand Unified Theory (GUT) epoch, the Electroweak phase transition (where the electromagnetic and weak forces separated), and the Quantum Chromodynamics (QCD) phase transition (where quarks bound together to form protons and neutrons).

First-Order Phase Transitions (FOPT) Theoretical phys ...