Dynamical fluid-type Universe scenario with dust and radiation

TL;DR

This paper investigates a flat FRW cosmological model with mixed matter sources, including dust and stiff matter, analyzing the effects of a positive cosmological constant on the universe's dynamics and thermodynamics.

Contribution

It introduces a detailed analysis of a universe model with decoupled matter sources and a cosmological constant, focusing on geometrodynamics and thermodynamics within a flat geometry.

Findings

Cosmological constant significantly influences universe dynamics.

Thermodynamics of the model reveals specific relations between energy density and pressure.

The model provides insights into the effects of matter and dark energy components.

Abstract

Within the context of a cosmic space whose energy source is modeled with a perfect fluid, a uniform model of Universe based on a standard FRW cosmology containing decoupled mixed matter sources namely stiff matter and cosmic dust together with a positive cosmological constant, has been studied. Within the scenario of a $k=0-$ spatially-flat geometry, we analysed the geometrodynamics of the theoretical cosmology. For the model with an added cosmological constant, the main scope was to point out the effects of it on the universe' dynamics. In this last case, the thermodynamics of the model was also considered together with the relation between the cosmological energy density and fluid pressure in terms of the inverse function of the equation of state.