Stability of a noncanonical scalar field model during cosmological date

TL;DR

This paper investigates the cosmological implications of a non-canonical scalar field model with a nonlinear potential, analyzing its fixed points, evolution, and effects on matter perturbations across different universe epochs.

Contribution

It introduces a specific fixed point solution for a nonlinear scalar field model and explores its impact on cosmic evolution and structure formation.

Findings

Scalar field potential varies with scalar field and universe epoch.

Scalar field energy density suppresses matter perturbation growth at low redshifts.

Scalar field remains stable against gravitational perturbations in various epochs.

Abstract

Using the non-canonical model of scalar field, the cosmological consequences of a pervasive, self-interacting, homogeneous and rolling scalar field are studied. In this model, the scalar field potential is nonlinear and decreases in magnitude with increasing the value of the scalar field. A special solution of the nonlinear field equation of phi that has time dependency as fixed point is obtained. The point relies on the non-canonical term of action and gamma parameter, this parameter is appeared in energy density of scalar field red shift. By means of such fixed point the different eigenvalues of the equation of motion of will be obtained. In different epochs in the evolution of the universe for different values of q and n the potentials as a function of scalar field are attained. The behavior of baryonic perturbations in linear perturbation scenario as a considerable amount of energy density of scalar field at low red shifts prevents the growth of perturbations in the ordinary matter fluid. The energy density in the scalar field is not appreciably perturbed by non-relativistic gravitational fields, either in the radiation or matter dominant, or scalar field dominated epoch.