A k-essence Model Of Inflation, Dark Matter and Dark Energy

TL;DR

This paper explores a extit{k}-essence scalar field model that unifies inflation, dark matter, and dark energy, demonstrating its potential to replicate key cosmological features and fitting observational data.

Contribution

It introduces a extit{k}-essence model with a potential and non-canonical kinetic term that successfully reproduces inflation, dark matter, and dark energy stages.

Findings

The purely kinetic extit{k}-essence model leads to a static universe.

A extit{k}-essence model with potential can generate inflation, dark matter, and dark energy.

The model parameters are constrained by observational data.

Abstract

We investigate the possibility for \textit{k}-essence dynamics to reproduce the primary features of inflation in the early universe, generate dark matter subsequently, and finally account for the presently observed acceleration. We first show that for a purely kinetic \textit{k}-essence model the late time energy density of the universe when expressed simply as a sum of a cosmological constant and a dark matter term leads to a static universe. We then study another \textit{k}-essence model in which the Lagrangian contains a potential for the scalar field as well as a non-canonical kinetic term. We show that such a model generates the basic features of inflation in the early universe, and also gives rise to dark matter and dark energy at appropriate subsequent stages. Observational constraints on the parameters of this model are obtained.