Intrinsic limits on the detection of the anisotropies of the Stochastic Gravitational Wave Background
Abstract
For any given network of detectors, and for any given integration time, even in the idealized limit of negligible instrumental noise, the intrinsic time variation of the isotropic component of the Stochastic Gravitational Wave Background (SGWB) induces a limit on how accurately the anisotropies in the SGWB can be measured. We show here how this sample limit can be calculated and apply this to three separate configurations of groundbased detectors placed at existing and planned sites. Our results show that in the idealized, bestcase scenario individual multipoles of the anisotropies at $\ell \leq 8$ can only be measured to $\sim 10^{5}  10^{4}$ level over 5 years of observation as a fraction of the isotropic component. As the sensitivity improves as the square root of the observation time, this poses a very serious challenge for the measurement of the anisotropies of SGWB of cosmological origin, even in the case of idealised detectors with arbitrarily low instrumental noise.
 Publication:

arXiv eprints
 Pub Date:
 January 2023
 DOI:
 10.48550/arXiv.2301.08074
 arXiv:
 arXiv:2301.08074
 Bibcode:
 2023arXiv230108074M
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 5 pages, 2 figures