Anisotropies in the Gravitational-Wave Stochastic Background

TL;DR

This paper develops a formalism to analyze anisotropies in the stochastic gravitational-wave background caused by fluctuations in source numbers, applying it specifically to cosmic string loops with cusps and kinks.

Contribution

It introduces a general formalism for anisotropy analysis in the gravitational-wave background and applies it to cosmic string scenarios, providing detailed angular and frequency dependence.

Findings

Anisotropies depend on source fluctuations and are calculable for different models.

Cosmic string cusps and kinks produce distinct anisotropy signatures.

Results inform future gravitational-wave observations and source modeling.

Abstract

We consider anisotropies in the stochastic background of gravitational-waves (SBGW) arising from random fluctuations in the number of gravitational-wave sources. We first develop the general formalism which can be applied to different cosmological or astrophysical scenarios. We then apply this formalism to calculate the anisotropies of SBGW associated with the fluctuations in the number of cosmic string loops, considering both cosmic string cusps and kinks. We calculate the anisotropies as a function of angle and frequency.