A simple nonsingular inflationary quintessential model

TL;DR

This paper proposes a nonsingular inflationary quintessential cosmological model within flat FLRW geometry, featuring a nonlinear fluid equation of state, phase transitions, and compatibility with Planck data, offering an analytic solution for cosmic evolution.

Contribution

It introduces a novel nonsingular inflationary model with an analytic solution, unifying early inflation and late acceleration, and fitting observational data better than existing potentials.

Findings

Nonsingular universe evolution from inflation to acceleration

Model fits Planck cosmological perturbation data

Analytic solutions enable detailed theoretical analysis

Abstract

In the framework of a flat Friedmann-Lema{\^\i}tre-Robertson-Walker (FLRW) geometry, we present a nonsingular model (no big bang singularity at finite time) of our universe describing its evolution starting from its early inflationary era up to the present accelerating phase. We found that a hydrodynamical fluid with nonlinear equation of state could result in such a non singular scenario, which after the end of this inflationary stage, suffers a sudden phase transition and enters into the stiff matter dominated era, and the universe becomes reheated due to a huge amount of particle production. Finally, it asymptotically enters into the de Sitter phase concluding the present accelerated expansion. We show that the background providing an inflationary potential leads to a power spectrum of the cosmological perturbations which fit well with the latest Planck estimations. At the end, we compared our viable potential with some known inflationary quintessential potentials, which shows that, our model is an improved version of them because it contains an analytic solution that allows us to perform analytic calculations.