Some Aspects of Tachyon Field Cosmology

TL;DR

This paper investigates the cosmological implications of tachyon fields, analyzing inflation, perturbations, and late-time behavior, while comparing model predictions with observational data and exploring phase space stability.

Contribution

It provides a comprehensive analysis of both minimally and non-minimally coupled tachyon fields in cosmology, including phase space dynamics and statefinder diagnostics.

Findings

Stable fixed points corresponding to mbda CDM scenario

Model viability confirmed against observational data

Phase space analysis reveals stability of late-time solutions

Abstract

We study inflation, perturbations, non-gaussinity and late-time cosmological dynamics of a tachyon field both minimally and non-minimally coupled to gravity. By analyzing the parameters space of the model, the viability of the model in confrontation with recent observational data is considered. In a dynamical system technique, we study the phase space dynamics of both minimally and non-minimally coupled tachyon field. We find the fixed points (lines in our setup) and explore their stability. Also, we perform a statefinder diagnostic to both cases and show that the trajectories of the state finder pairs reach a stable state which is corresponding to a $\Lambda$CDM scenario.