Radiation dominated era and the power of general relativity

TL;DR

This paper derives bounds on a modified gravity theory during the radiation dominated era, showing that recent constraints effectively rule out the R^{1+epsilon} modification of general relativity.

Contribution

It provides new bounds on the R^{1+epsilon} gravity theory using radiation era analysis, conclusively ruling out this modification.

Findings

Bounds on R^{1+epsilon} gravity are tightened during the radiation era.

The R^{1+epsilon} theory is ruled out by combined constraints.

Previous and new bounds together exclude the theory entirely.

Abstract

An analysis in the framework of the radiation dominated era permits to put bounds on the weak modification of general relativity which arises from the Lagrangian R^{1+epsilon}. Such a theory has been recently discussed in various papers in the literature. The new bounds together with previous ones in the literature rule out this theory in an ultimate way.