Nonsingular cosmology from evolutionary quantum gravity

TL;DR

This paper models a nonsingular, bouncing early Universe using evolutionary quantum gravity with a negative cosmological constant and a scalar field, resulting in a consistent preinflationary and late-time cosmology.

Contribution

It introduces a quantum cosmological model with a primordial bounce and a high occupation number ground state, linking quantum gravity to observable late-time Universe behavior.

Findings

Universe exhibits a nonsingular bounce due to quantum effects.

Ground state has a high occupation number and negative super-Hamiltonian eigenvalue.

Model aligns with current observations and predicts a future turning point.

Abstract

We provide a cosmological implementation of the evolutionary quantum gravity, describing an isotropic Universe, in the presence of a negative cosmological constant and a massive (preinflationary) scalar field. We demonstrate that the considered Universe has a nonsingular quantum behavior, associated to a primordial bounce, whose ground state has a high occupation number. Furthermore, in such a vacuum state, the super-Hamiltonian eigenvalue is negative, corresponding to a positive emerging dust energy density. The regularization of the model is performed via a polymer quantum approach to the Universe scale factor and the proper classical limit is then recovered, in agreement with a preinflationary state of the Universe. Since the dust energy density is redshifted by the Universe deSitter phase and the cosmological constant does not enter the ground state eigenvalue, we get a late-time cosmology, compatible with the present observations, endowed with a turning point in the far future.