Two non-commutative parameters and regular cosmological phase transition in the semi-classical dilaton cosmology

TL;DR

This paper investigates how introducing two non-commutative parameters in semi-classical dilaton gravity models leads to a smooth cosmological phase transition, avoiding initial singularities and resulting in an accelerated expansion phase.

Contribution

It introduces a novel approach using two non-commutative parameters to model singularity-free cosmological phase transitions in semi-classical dilaton gravity.

Findings

Universe transitions between accelerated and decelerated expansion phases.

Final universe state approaches flat spacetime regardless of initial curvature.

Initial-singularity-free condition correlates with second accelerated expansion.

Abstract

We study cosmological phase transitions from modified equations of motion by introducing two non-commutative parameters in the Poisson brackets, which describes the initial- and future-singularity-free phase transition in the soluble semi-classical dilaton gravity with a non-vanishing cosmological constant. Accelerated expansion and decelerated expansion corresponding to the FRW phase appear alternatively, and then it ends up with the second accelerated expansion. The final stage of the universe approaches the flat spacetime independent of the initial state of the curvature scalar as long as the product of the two non-commutative parameters is less than one. Finally, we show that the initial-singularity-free condition is related to the second accelerated expansion of the universe.