Modified theory of gravity and the history of cosmic evolution

TL;DR

This paper proposes a modified gravity theory that models the entire cosmic history, including early radiation, matter domination, late acceleration, and a secondary radiation era, potentially explaining reionization phenomena.

Contribution

It introduces a unified modified gravity framework that accounts for the full cosmic evolution without additional components.

Findings

Successfully models the sequence of cosmic eras within a single theory.

Suggests a new explanation for hydrogen and helium reionization at low redshift.

Provides a continuous transition between different cosmic phases.

Abstract

A continuous transition from early Friedmann-like radiation era through to late time cosmic acceleration passing through a long Friedmann-like matter dominated era followed by a second phase of radiation era has been realized in modified theory of gravity containing a combination of curvature squared term, a linear term, a three-half term and an ideal fluid. Thus the history of cosmic evolution is explained by modified theory of gravity singlehandedly. The second phase of radiation-like era might provide an explanation to the hydrogen and helium reionization at low redshift.