Bounce inflation in $f(T)$ Cosmology: A unified inflaton-quintessence field

TL;DR

This paper proposes a bounce inflation model within $f(T)$ gravity that unifies inflaton and quintessence fields, predicts a nearly scale-invariant power spectrum, and describes a self-accelerating universe with a consistent thermal history.

Contribution

It introduces a novel $f(T)$ bounce inflation model that unifies inflaton and quintessence fields and analyzes its thermal evolution and primordial fluctuations.

Findings

The universe undergoes a supercold precontraction phase.

The model predicts a maximum temperature below GUT scale during reheating.

The power spectrum is nearly scale invariant.

Abstract

We investigate a bounce inflation model with a graceful exit into the Friedmann-Robertson-Walker (FRW) decelerated Universe within $f(T)$ gravity framework, where $T$ is the torsion scalar in the teleparallelism. We study the cosmic thermal evolution, the model predicts a supercold Universe during the precontraction phase, which is consistent with the requirements of the slow-roll models, while it performs a reheating period by the end of the contraction with a maximum temperature just below the grand unified theory (GUT) temperature. However, it matches the radiation temperature of the hot big bang at later stages. The equation-of-state due to the effective gravitational sector suggests that our Universe is self-accelerated by teleparallel gravity. We assume the matter component to be a canonical scalar field. We obtain the scalar field potential that is induced by the $f(T)$ theory. The power spectrum of the model is nearly scale invariant. In addition, we show that the model unifies inflaton and quintessence fields in a single model. Also, we revisited the primordial fluctuations in $f(T)$ bounce cosmology, to study the fluctuations that are produced at the precontraction phase.