Higher-order gravity and the cosmological background of gravitational waves

TL;DR

This paper explores how higher-order modifications to gravity, specifically an $R^{1+ ext{epsilon}}$ correction, influence the evolution and generation of gravitational waves in the early universe, providing a parametric framework for their study.

Contribution

It introduces a parametric approach using $R^{1+ ext{epsilon}}$ gravity to control gravitational wave background evolution and production in cosmology.

Findings

Higher-order gravity corrections can tune the gravitational wave background.

The $R^{1+ ext{epsilon}}$ model offers a flexible framework for early universe gravitational wave studies.

Potential implications for gravitational wave detection and cosmological models.

Abstract

The cosmological background of gravitational waves can be tuned by the higher-order corrections to the gravitational Lagrangian. In particular, it can be shown that assuming $R^{1+\epsilon}$, where $\epsilon$ indicates a generic (eventually small) correction to the Hilbert-Einstein action in the Ricci scalar $R$, gives a parametric approach to control the evolution and the production mechanism of gravitational waves in the early Universe.