Matter–antimatter asymmetry and other cosmological puzzles via running vacuum cosmologies

Abstract

Current astronomical observations are successfully explained by the present cosmological paradigm based on the concordance model ([Formula: see text]CDM + Inflation). However, such a scenario is composed of a heterogeneous mix of ingredients for describing the different stages of cosmological evolution. Particularly, it does not give a unified explanation connecting the early- and late-time accelerating inflationary regimes which are separated by many aeons. Other challenges to the concordance model include: a singularity at early times or the emergence of the universe from the quantum gravity regime, the “graceful” exit from inflation to the standard radiation phase, as well as, the coincidence and cosmological constant problems. We show here that a simple running vacuum model or a time-dependent vacuum may provide insight on some of the above open questions (including a complete cosmic history), and also can explain the observed matter–antimatter asymmetry just after the initial deflationary period.