Thermal Vacuum Model for Cosmology without Inflaton

TL;DR

This paper proposes a cosmological model replacing the inflaton and dark energy with a thermal vacuum in an expanding universe, explaining inflation, late-time acceleration, baryogenesis, and constraining dark matter properties.

Contribution

It introduces a novel thermal vacuum model for cosmology that eliminates the need for inflaton and dark energy, providing mechanisms for inflation, acceleration, and baryogenesis.

Findings

Provides a new inflation mechanism with graceful exit

Explains late-time cosmic acceleration without dark energy

Suggests bounds on dark matter particle properties

Abstract

The previously proposed modification of the standard (flat) inflationary $\Lambda CDM$ model in which the inflaton field(s) and ``dark energy" are replaced by the vacum in expanding Friedmann-Lema\^itre-Robertson-Walker Universe is studied. The expanding joint vacuum of the all ingrediences of matter, including Standard Model particles and a dark matter sector, is treated as a thermal equilibrium state at temporal Gibbons-Hawking temperature, proportional to the Hubble parameter, and chemical potentials equal to particle masses. This theory provides not only the new mechanism of inflation and its graceful exit, but also explains acceleration of expansion for the late Universe. The formalism can be combined with the anomalous quantum gravity effects leading to a viable baryogenesis mechanism and certain bounds on dark matter particle masses and lifetimes.