Singularity Avoidance in Nonlinear Quantum Cosmology

TL;DR

This paper investigates how nonlinear corrections to the Wheeler-deWitt equation can prevent the initial singularity in various quantum cosmological models, extending previous work to include hyperbolic geometries and broader initial states.

Contribution

It demonstrates that nonlinear quantum effects can avoid singularities in hyperbolic universes and generalizes singularity avoidance results to a wider class of initial states in flat universes.

Findings

Nonlinear corrections create barriers preventing initial singularities in hyperbolic universes.

Singularity avoidance is perturbatively achievable for many initial states in flat universe models.

The results extend previous flat universe findings to more general geometries and states.

Abstract

We extend our previous study on the effects of an information-theoretically motivated nonlinear correction to the Wheeler-deWitt equation in the minisuperspace scheme for FRW universes. Firstly we show that even when the geometry is hyperbolic, and matter given by a cosmological constant, the nonlinearity can still provide a barrier to screen the initial singularity, just as in the case for flat universes. Secondly, in the flat case we show that singularity avoidance in the presence of a free massless scalar field is perturbatively possible for a very large class of initially unperturbed quantum states, generalising our previous discussion using Gaussian states.