Bose-Einstein condensation as an alternative to inflation

TL;DR

This paper proposes that Bose-Einstein condensation of gravitons in the early Universe can explain dark matter, dark energy, large-scale homogeneity, flatness, and scale-invariant perturbations, offering an alternative to inflation.

Contribution

It introduces a novel cosmological model where graviton condensates account for key universe properties without inflation.

Findings

Graviton condensate explains dark matter and dark energy.

Condensation accounts for universe's homogeneity and flatness.

Quantum fluctuations produce scale-invariant spectrum.

Abstract

It was recently shown that gravitons with a very small mass should have formed a Bose-Einstein condensate in the very early Universe, whose density and quantum potential can account for the dark matter and dark energy in the Universe respectively. Here we show that the condensation can also naturally explain the observed large scale homogeneity and isotropy of the Universe. Furthermore gravitons continue to fall into their ground state within the condensate at every epoch, accounting for the observed flatness of space at cosmological distances scales. Finally, we argue that the density perturbations due to quantum fluctuations within the condensate give rise to a scale invariant spectrum. This therefore provides a viable alternative to inflation, which is not associated with the well-known problems associated with the latter.