First predictions of the angular power spectrum of the astrophysical gravitational wave background

TL;DR

This paper predicts the angular power spectrum of the astrophysical gravitational wave background, revealing its dependence on astrophysical and cosmological factors, and explores its correlations with weak-lensing and galaxy distribution.

Contribution

First predictions of the angular power spectrum of the astrophysical gravitational wave background, linking astrophysics and cosmology.

Findings

Angular power spectrum scales as 1/ell on large scales.

Relative fluctuations are about 30% at 100 Hz.

Correlations with weak-lensing and galaxy distribution are analyzed.

Abstract

We present the first predictions for the angular power spectrum of the astrophysical gravitational wave background constituted of the radiation emitted by all resolved and unresolved astrophysical sources. Its shape and amplitude depend on both the astrophysical properties on galactic scales and on cosmological properties. We show that the angular power spectrum behaves as $C_{\ell}\propto 1/{\ell}$ on large scales and that relative fluctuations of the signal are of order 30% at 100 Hz. We also present the correlations of the astrophysical gravitational wave background with weak-lensing and galaxy distribution. These numerical results pave the way to the study of a new observable at the crossroad between general relativity, astrophysics and cosmology.