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arXiv · 2205.05644

Enhancing gravitational wave anisotropies with peaked scalar sources

Ema Dimastrogiovanni·Matteo Fasiello·Ameek Malhotra·Gianmassimo Tasinato
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Abstract

Gravitational wave (GW) backgrounds of cosmological origin are expected to be nearly isotropic, with small anisotropies resembling those of the cosmic microwave background. We analyse the case of a scalar-induced GW background and clarify in the process the relation between two different approaches to calculating GW anisotropies. We focus on GW scenarios sourced by a significantly peaked scalar spectrum, which are frequently considered in the context of primordial black holes production. We show that the resulting GW anisotropies are characterised by a distinct frequency dependence. We explore the observational consequences concentrating on a GW background enhanced in the frequency band of space-based GW detectors. We study the detectability of the signal through both cross-correlations among different space-based GW detectors, and among GW and CMB experiments.

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Ema Dimastrogiovanni, Matteo Fasiello, Ameek Malhotra, Gianmassimo Tasinato. 2022-05-11. Enhancing gravitational wave anisotropies with peaked scalar sources. https://doi.org/10.1088/1475-7516%2F2023%2F01%2F018

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