English

Enhancing gravitational wave anisotropies with peaked scalar sources

Cosmology and Nongalactic Astrophysics 2023-01-18 v2 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology High Energy Physics - Theory

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.

Keywords

Cite

@article{arxiv.2205.05644,
  title  = {Enhancing gravitational wave anisotropies with peaked scalar sources},
  author = {Ema Dimastrogiovanni and Matteo Fasiello and Ameek Malhotra and Gianmassimo Tasinato},
  journal= {arXiv preprint arXiv:2205.05644},
  year   = {2023}
}

Comments

31 pages, 6 figures. Version accepted at JCAP