Constraining modified theories of gravity with gravitational wave stochastic background

TL;DR

This paper explores how gravitational wave backgrounds can be used to test and constrain modified theories of gravity, potentially surpassing current bounds from pulsar observations.

Contribution

It models the impact of modified gravity theories using the ppE formalism on stochastic gravitational wave backgrounds and assesses their detectability with ground-based interferometers.

Findings

AdLIGO can set significant new constraints on modified gravity theories.

The stochastic background analysis can improve bounds over binary pulsar observations.

Ground-based detectors have potential to test fundamental physics beyond General Relativity.

Abstract

The direct discovery of gravitational waves has finally opened a new observational window on our Universe, suggesting that the population of coalescing binary black holes is larger than previously expected. These sources produce an unresolved background of gravitational waves, potentially observables by ground-based interferometers. In this paper we investigate how modified theories of gravity, modeled using the ppE formalism, affect the expected signal, and analyze the detectability of the resulting stochastic background by current and future ground-based interferometers. We find the constraints that AdLIGO would be able to set on modified theories, showing that they may significantly improve the current bounds obtained from astrophysical observations of binary pulsars.