Spatially-Flat Robertson-Walker models with combined CDM and stiff matter sources and the corresponding thermodynamics

TL;DR

This paper analyzes a flat cosmological model with stiff matter and dust, deriving the scale factor and thermodynamic relations, including the equation of state, energy density, and pressure dependence on temperature.

Contribution

It introduces a combined stiff matter and dust model with thermodynamic analysis, deriving explicit relations for energy density and pressure as functions of temperature.

Findings

Derived the scale function and cosmological parameters.

Obtained the general form of the equation of state.

Established explicit temperature dependence of energy density and pressure.

Abstract

In the present paper, we are considering a spatially-flat Friedmann-Robertson-Walker cosmological model, fueled with stiff matter and dust, treated as non-interacting ideal fluid sources. By solving the corresponding Friedmann equation with a non-zero cosmological constant, we are deriving the scale function and the fundamental cosmological parameters. Within a thermodynamic approach, the general form of the Equation of State is obtained, together with the explicit dependence of the energy density and pressure on temperature.