In physical cosmology, baryogenesis is the generic term for hypothetical physical processes that produced an asymmetry between baryons and antibaryons in the very early universe, resulting in the substantial amounts of residual matter that make up the universe today.
Baryogenesis theories (the most important being electroweak baryogenesis and GUT baryogenesis) employ sub-disciplines of physics such as quantum field theory, and statistical physics,
to describe such possible mechanisms. The fundamental difference
between baryogenesis theories is the description of the interactions
between fundamental particles.
The next step after baryogenesis is the much better understood Big Bang nucleosynthesis, during which light atomic nuclei began to form.