Characterizing the Cosmological Gravitational Wave Background Anisotropies and non-Gaussianity

Abstract

A future detection of the Stochastic Gravitational Wave Background (SGWB) with GW experiments is expected to open a new window on early universe cosmology and on the astrophysics of compact objects. In this paper we study SGWB anisotropies, that can offer new tools to discriminate between different sources of GWs. In particular, the cosmological SGWB inherits its anisotropies both (i) at its production and (ii) during its propagation through our perturbed universe. Concerning (i), we show that it typically leads to anisotropies with order one dependence on frequency. We then compute the effect of (ii) through a Boltzmann approach, including contributions of both large-scale scalar and tensor linearized perturbations. We also compute for the first time the three-point function of the SGWB energy density, which can allow one to extract information on GW non-Gaussianity with interferometers. Finally, we include non-linear effects associated with long wavelength scalar fluctuations, and compute the squeezed limit of the 3-point function for the SGWB density contrast. Such limit satisfies a consistency relation, conceptually similar to what found in the literature for the case of CMB perturbations.

26 pages + Appendices: 2 figures

References in corpus (20)

• Laser Interferometer Space Antenna
• Exploring the Sensitivity of Next Generation Gravitational Wave Detectors
• Science Case for the Einstein Telescope
• Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves
• Large Nongaussianity in Axion Inflation
• Reconstructing the spectral shape of a stochastic gravitational wave background with LISA
• Gravitational waves at interferometer scales and primordial black holes in axion inflation
• Planck 2018 results. IX. Constraints on primordial non-Gaussianity
• Anisotropies and non-Gaussianity of the Cosmological Gravitational Wave Background
• Gravitational wave radiometry: Mapping a stochastic gravitational wave background
• Gravitational Wave Anisotropies from Primordial Black Holes
• Detection methods for non-Gaussian gravitational wave stochastic backgrounds
• Projection effects on the observed angular spectrum of the astrophysical stochastic gravitational wave background
• Measuring the net circular polarization of the stochastic gravitational wave background with interferometers
• Searching for Fossil Fields in the Gravity Sector
• Improved limits on a stochastic gravitational-wave background and its anisotropies from Advanced LIGO O1 and O2 runs
• Probing anisotropies of gravitational-wave backgrounds with a space-based interferometer III: Reconstruction of a high-frequency skymap
• Non-Gaussianity analysis of GW background made by short-duration burst signals
• Probing a stationary non-Gaussian background of stochastic gravitational waves with pulsar timing arrays
• Non-Gaussianity test for discriminating gravitational wave backgrounds around 0.1-1Hz

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• The Gravitational-Wave Physics II: Progress
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• Implications of Pulsar Timing Array Data for Scalar-Induced Gravitational Waves and Primordial Black Holes: Primordial Non-Gaussianity $f_{\mathrm{NL}}$ Considered
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• Estimating the gravitational wave background anisotropy: a Bayesian approach boosted by cross-correlation angular power spectrum
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