Cosmological analytic solutions with reduced relativistic gas

TL;DR

This paper derives analytical solutions for flat and non-flat universes with four components, including a novel treatment of warm matter as a reduced relativistic gas, but does not find solutions with all four components simultaneously.

Contribution

It introduces analytical solutions incorporating warm matter as a reduced relativistic gas in cosmological models with multiple components.

Findings

Solutions with one, two, or three components were obtained.

A solution involving all four components was not found.

The warm matter component is treated as a reduced relativistic gas.

Abstract

In this paper one examine analytical solutions for flat and non-flat universes composed by four components namely hot matter (ultra-relativistic), warm matter (relativistic), cold matter (non-relativistic) and cosmological constant. The warm matter is treated as a reduced relativistic gas and the other three components are treated in the usual way. The solutions achieved contains one, two or three components of which one component is of warm matter type. A solution involving all the four components was not found.