On the quantum fate of singularities in a dark-energy dominated universe

TL;DR

This paper investigates whether quantum cosmology can resolve certain classical singularities in dark-energy dominated universes, finding solutions to the Wheeler-DeWitt equation that avoid these singularities.

Contribution

It demonstrates that specific quantum solutions can eliminate classical singularities in models with generalized Chaplygin gas, advancing understanding of quantum effects on cosmic singularities.

Findings

Quantum solutions satisfying DeWitt's criterion exist.

Such solutions can avoid classical singularities.

Ambiguity remains in selecting the unique solution.

Abstract

Classical models for dark energy can exhibit a variety of singularities, many of which occur for scale factors much bigger than the Planck length. We address here the issue whether some of these singularities, the big freeze and the big demarrage, can be avoided in quantum cosmology. We use the framework of quantum geometrodynamics. We restrict our attention to a class of models whose matter content can be described by a generalized Chaplygin gas and be represented by a scalar field with an appropriate potential. Employing the DeWitt criterium that the wave function be zero at the classical singularity, we show that a class of solutions to the Wheeler-DeWitt equation fulfilling this condition can be found. These solutions thus avoid the classical singularity. We discuss the reasons for the remaining ambiguity in fixing the solution.