Accelerating universe in two-dimensional noncommutative dilaton cosmology

TL;DR

This paper demonstrates that in a two-dimensional noncommutative dilaton gravity model, a phase transition from decelerating to accelerating universe can occur due to quantum effects, providing insights into cosmological acceleration.

Contribution

It introduces a novel approach by incorporating noncommutative field variables in semiclassical two-dimensional dilaton gravity to explain universe acceleration.

Findings

Quantum-induced energy causes early universe deceleration.

Transition to acceleration occurs as dilaton-driven cosmology dominates.

Model offers a potential explanation for the cosmological coincidence problem.

Abstract

We show that the phase transition from the decelerating universe to the accelerating universe, which is of relevance to the cosmological coincidence problem, is possible in the semiclassically quantized two-dimensional dilaton gravity by taking into account the noncommutative field variables during the finite time. Initially, the quantum-mechanically induced energy from the noncommutativity among the fields makes the early universe decelerate and subsequently the universe is accelerating because the dilaton driven cosmology becomes dominant later.