The stochastic gravitational wave background (SGWB) is expected to be a key observable for gravitational wave (GW) interferometry. Its detection will open a new window to early Universe cosmology and to the astrophysics of compact objects. Using a Boltzmann approach, we study the angular anisotropies of the GW energy density, which is an important tool to disentangle the different cosmological and astrophysical contributions to the SGWB. Anisotropies in the cosmological background are imprinted both at its production and by GW propagation through the large-scale scalar and tensor perturbations of the Universe. The first contribution is not present in the cosmic microwave background radiation (as the Universe is not transparent to photons before recombination), causing an order 1 dependence of the anisotropies on frequency. Moreover, we provide a new method to characterize the cosmological SGWB through its possible deviation from Gaussian statistics. In particular, the SGWB will become a new probe of the primordial non-Gaussianity of the large-scale cosmological perturbations.

Anisotropies and non-Gaussianity of the Cosmological Gravitational Wave Background

Ricciardone, A.;
2019-01-01

Abstract

The stochastic gravitational wave background (SGWB) is expected to be a key observable for gravitational wave (GW) interferometry. Its detection will open a new window to early Universe cosmology and to the astrophysics of compact objects. Using a Boltzmann approach, we study the angular anisotropies of the GW energy density, which is an important tool to disentangle the different cosmological and astrophysical contributions to the SGWB. Anisotropies in the cosmological background are imprinted both at its production and by GW propagation through the large-scale scalar and tensor perturbations of the Universe. The first contribution is not present in the cosmic microwave background radiation (as the Universe is not transparent to photons before recombination), causing an order 1 dependence of the anisotropies on frequency. Moreover, we provide a new method to characterize the cosmological SGWB through its possible deviation from Gaussian statistics. In particular, the SGWB will become a new probe of the primordial non-Gaussianity of the large-scale cosmological perturbations.
2019
Bartolo, N.; Bertacca, D.; Matarrese, S.; Peloso, M.; Ricciardone, A.; Riotto, A.; Tasinato, G.
File in questo prodotto:
File Dimensione Formato  
Angelo_Ricciardone_9.pdf

accesso aperto

Tipologia: Versione finale editoriale
Licenza: Creative commons
Dimensione 208.95 kB
Formato Adobe PDF
208.95 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/1167508
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 75
  • ???jsp.display-item.citation.isi??? 71
social impact