SU(2)R and its axion in cosmology: A common origin for inflation, cold sterile neutrinos, and baryogenesis.

We introduce an axion-inflation model embedded in the left-right symmetric extension of the Standard Model in which WR is coupled to the axion. This model merges three milestones of modern cosmology, i.e., inflation, cold dark matter, and baryon asymmetry. Thus, it can naturally explain the observed coincidences among cosmological parameters, i.e., ηB ≈ Pζ and ΩDM ≃ 5ΩB. The source of asymmetry is spontaneous CP violation in the physics of inflation, and the lightest right-handed neutrino is the cold dark matter candidate with mass mN1 ∼ 1 GeV. The introduced mechanism does not rely on the largeness of the unconstrained CP-violating phases in the neutrino sector or fine-tuned masses for the heaviest right-handed neutrinos. It has two unknown fundamental scales, i.e., scale of inflation Λinf = √HMPl and left-right symmetry breaking ΛF. Sufficient matter asymmetry demands that Λinf ≈ ΛF. Baryon asymmetry and dark matter today are remnants of a pure quantum effect (chiral anomaly) in inflation, which, thanks to flavor effects, has been memorized by cosmic evolution. [ABSTRACT FROM AUTHOR]