Scalar field power-law cosmology with spatial curvature and dark energy-dark matter interaction

TL;DR

This paper investigates a scalar field power-law cosmology with spatial curvature and dark energy-dark matter interaction, using observational data to determine model parameters and analyze the effects of interaction on the scalar potential.

Contribution

It provides a detailed analysis of scalar field potentials and interaction effects in a power-law universe constrained by observational data.

Findings

Power-law exponent $oldsymbol{eta}$ close to 1, consistent with observations.

Interaction slightly lowers scalar potential height and shifts potential curves.

Mass potential decays exponentially over time.

Abstract

We consider a late closed universe of which scale factor is a power function of time using observational data from combined WMAP5+BAO+SNIa dataset and WMAP5 dataset. The WMAP5 data give power-law exponent, $\alpha = 1.01$ agreeing with the previous study of $H(z)$ data while combined data gives $\alpha=0.985$. Considering a scalar field dark energy and dust fluid evolving in the power-law universe, we find field potential, field solution and equation of state parameters. Decaying from dark matter into dark energy is allowed in addition to the non-interaction case. Time scale characterizing domination of the kinematic expansion terms over the dust and curvature terms in the scalar field potential are found to be approximately 5.3 to 5.5 Gyr. The interaction affects in slightly lowering the height of scalar potential and slightly shifting potential curves rightwards to later time. Mass potential function of the interacting Lagrangian term is found to be exponentially decay function.