Horizon Problem Remediation via Deformed Phase Space

TL;DR

This paper explores how a specific dynamical deformation in Brans-Dicke cosmology can address the horizon problem, remove the big bang singularity, and produce late-time acceleration, suggesting quantum gravity effects influence cosmic evolution.

Contribution

It introduces a novel deformation approach in Brans-Dicke theory that impacts cosmological solutions, including singularity removal and horizon problem resolution.

Findings

One class of solutions yields a constant late-time scale factor.

Another class removes the big bang singularity.

The model predicts an infinite acceleration period solving the horizon problem.

Abstract

We investigate the effects of a special kind of dynamical deformation between the momenta of the scalar field of the Brans-Dicke theory and the scale factor of the FRW metric. This special choice of deformation includes linearly a deformation parameter. We trace the deformation footprints in the cosmological equations of motion when the BD coupling parameter goes to infinity. One class of the solutions gives a constant scale factor in the late time that confirms the previous result obtained via another approach in the literature. This effect can be interpreted as a quantum gravity footprint in the coarse grained explanation. The another class of the solutions removes the big bang singularity, and the accelerating expansion region has an infinite temporal range which overcomes the horizon problem. After this epoch, there is a graceful exiting by which the universe enters in the radiation dominated era.