Symmetry breaking and the onset of cosmic acceleration in scalar field models

TL;DR

This paper introduces a novel scalar field model where symmetry breaking triggers cosmic acceleration, with the scalar field climbing its potential and interactions leading to a positive cosmological constant for sustained acceleration.

Contribution

It proposes a new symmetry breaking mechanism in coupled dark energy models that explains the onset of cosmic acceleration and the possibility of a permanent late-time acceleration.

Findings

Symmetry breaking can induce the scalar field to climb its potential, initiating acceleration.

Interaction between dark sectors can lead to a stable vacuum with positive cosmological constant.

The model allows for a transition to a universe with eternal acceleration.

Abstract

We propose a new scenario for the onset of positive acceleration of our Universe based on symmetry breaking in coupled dark energy scalar field model. In a symmetry breaking process where the scalar field rolls down its own potential, the potential reduction is not in favor of acceleration. In our model, when dark matter density becomes less than a critical value, the shape of the effective potential is changed and, the quintessence field climbs up along {\it{its own potential}} while rolls down the effective potential. We show that this procedure may establish the positivity of the potential required for the Universe to accelerate. In addition, we show that by choosing an appropriate interaction between dark sectors there is the possibility that the scalar field resides in a new vacuum giving rise to a positive cosmological constant which is responsible for a permanent late time acceleration.