Mechanism behind the matter–antimatter asymmetry

Identify the physical symmetry-breaking mechanism(s) that produced the observed excess of matter over antimatter in the Universe.

Background

The text lists the baryon asymmetry as a major unresolved issue in cosmology, noting that the specific symmetry-breaking processes that led to today’s matter-dominated Universe are not yet understood. This encompasses, but is not limited to, questions of CP violation and baryogenesis mechanisms.

References

b) Asymmetry between matter and antimatter - we do not know the reason for the breaking of certain types of symmetry in physics, which resulted in the appearance of far more matter than antimatter in the Universe;

— Did the Big Bang and cosmic inflation really happen? (A tale of alternative cosmological models) (2404.18503 - Postolak, 29 Apr 2024) in The Big Bang... or what all the fuss is about — Limitations list (b)