A tachyonic scalar field with mutually interacting components

TL;DR

This paper explores different interaction models between matter and cosmological constant within a tachyonic scalar field framework, analyzing their effects on universe expansion and observational diagnostics.

Contribution

It introduces and compares various interaction forms between matter and the cosmological constant in a tachyonic scalar field context, using observational diagnostics.

Findings

Interaction forms influence the $O_{m}(x)$ diagnostic.

High- and low-redshift Hubble data help determine interaction parameters.

Different interactions lead to viable cosmological solutions.

Abstract

We investigate the tachyonic cosmological potential $V(\phi)$ in two different cases of the quasi-exponential expansion of universe and discuss various forms of interaction between the two components---matter and the cosmological constant--- of the tachyonic scalar field, which leads to the viable solutions of their respective energy densities. The distinction among the interaction forms is shown to appear in the $O_{m}(x)$ diagnostic. Further, the role of the high- and low-redshift observations of the Hubble parameter is discussed to determine the proportionality constants and hence the correct form of matter--cosmological constant interaction.