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Title: Probing anisotropies of the Stochastic Gravitational Wave Background with LISA
Abstract We investigate the sensitivity of the Laser Interferometer Space Antenna (LISA) to the anisotropies of the Stochastic Gravitational Wave Background (SGWB). We first discussthe main astrophysical and cosmological sources of SGWB which are characterized by anisotropies in the GW energy density, and we build a Signal-to-Noise estimator to quantify the sensitivity of LISA to different multipoles. We then perform a Fisher matrix analysis of the prospects of detectability of anisotropic features with LISA for individual multipoles, focusing on a SGWB with a power-law frequency profile. We compute the noise angular spectrum taking into account the specific scan strategy of the LISA detector. We analyze the case of the kinematic dipole and quadrupole generated by Doppler boosting an isotropic SGWB. We find that β Ω GW ∼ 2 × 10 -11 is required to observe a dipolar signal with LISA. The detector response to the quadrupole has a factor ∼ 10 3 β relative to that of the dipole. The characterization of the anisotropies, both from a theoretical perspective and from a map-making point of view, allows us to extract information that can be used to understand the origin of the SGWB, and to discriminate among distinct superimposed SGWB sources.  more » « less
Award ID(s):
1820675
NSF-PAR ID:
10384215
Author(s) / Creator(s):
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Date Published:
Journal Name:
Journal of Cosmology and Astroparticle Physics
Volume:
2022
Issue:
11
ISSN:
1475-7516
Page Range / eLocation ID:
009
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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