Physics of the early universe

The physics of the early universe involves extreme conditions shortly after the Big Bang, where temperatures and densities were unimaginably high. Under these conditions, particles such as quarks and gluons moved freely in a hot, dense plasma. As the universe expanded and cooled, these particles combined to form protons and neutrons, eventually leading to the formation of atoms, stars, and galaxies. Fundamental forces—gravity, electromagnetism, and nuclear forces—governed these processes, shaping the universe's evolution from a uniform, hot, and dense state to the complex cosmos we observe today.