GW_CLASS: Cosmological Gravitational Wave Background in the Cosmic Linear Anisotropy Solving System

TL;DR

This paper introduces GW_CLASS, a computational tool for analyzing the anisotropies of the Cosmological Gravitational Wave Background and its correlation with CMB, aiding in understanding early universe physics.

Contribution

The paper presents a new implementation of CGWB anisotropy calculations in a modified CLASS code, enabling detailed forecasts of future gravitational wave and CMB experiment sensitivities.

Findings

Efficient computation of CGWB anisotropy spectra

Forecasts for future gravitational wave and CMB experiment sensitivities

Analysis of primordial sources of gravitational waves

Abstract

The anisotropies of the Cosmological Gravitational Wave Background (CGWB) retain information about the primordial mechanisms that source the gravitational waves and about the geometry and the particle content of the universe at early times. In this work, we discuss in detail the computation of the angular power spectra of CGWB anisotropies and of their cross correlation with Cosmic Microwave Background (CMB) anisotropies, assuming different processes for the generation of these primordial signals. We present an efficient implementation of our results in a modified version of CLASS which will be publicly available. By combining our new code GW_CLASS with MontePython, we forecast the combined sensitivity of future gravitational wave interferometers and CMB experiments to the cosmological parameters that characterize the cosmological gravitational wave background.