A review of the stochastic background of gravitational waves in f(R) gravity with WMAP constrains

TL;DR

This review discusses the stochastic background of gravitational waves in f(R) gravity, utilizing WMAP data to explore how these waves can serve as probes for alternative gravity theories, updating previous COBE-based analyses.

Contribution

It demonstrates how SBGWs relate to f(R) gravity and proposes using SBGWs to test and constrain these theories with WMAP data, advancing the understanding of gravitational wave cosmology.

Findings

WMAP data provides updated constraints on SBGWs

f(R) theories can be parametrized through SBGWs analysis

Potential detection of high-frequency gravitational waves

Abstract

This paper is a review of previous works on the stochastic background of gravitational waves (SBGWs) which has been discussed in various peer-reviewed journals and international conferences. The SBGWs is analyzed with the aid of the Wilkinson Microwave Anisotropy Probe (WMAP) data. We emphasize that, in general, in previous works in the literature about the SBGWs, old Cosmic Background Explorer (COBE) data were used. After this, we want to face the problem of how the SBGWs and f(R) gravity (where f(R) is a function of the Ricci scalar R) can be related, showing, vice versa, that a revealed SBGWs could be a powerful probe for a given theory of gravity. In this way, it will also be shown that the conform treatment of SBGWs can be used to parametrize in a natural way f(R) theories. Some interesting examples which have been recently discussed in the literature will be also analysed. The presence and the potential detection of the SBGWs is quite important in the framework of the debate on high-frequency gravitational waves (HFGWs) too. Recently, the importance of HFGWs has been emphasized in some papers in the literature.