Uncovering gravitational-wave backgrounds from noises of unknown shape with LISA

Baghi, Q., Karnesis, N., Bayle, J.-B. , Besançon, M. and Inchauspé, H. (2023) Uncovering gravitational-wave backgrounds from noises of unknown shape with LISA. Journal of Cosmology and Astroparticle Physics, 2023(4), 66. (doi: 10.1088/1475-7516/2023/04/066)

[img] Text
296704.pdf - Published Version
Available under License Creative Commons Attribution.

1MB

Abstract

Detecting stochastic background radiation of cosmological origin is an exciting possibility for current and future gravitational-wave (GW) detectors. However, distinguishing it from other stochastic processes, such as instrumental noise and astrophysical backgrounds, is challenging. It is even more delicate for the space-based GW observatory LISA since it cannot correlate its observations with other detectors, unlike today's terrestrial network. Nonetheless, with multiple measurements across the constellation and high accuracy in the noise level, detection is still possible. In the context of GW background detection, previous studies have assumed that instrumental noise has a known, possibly parameterized, spectral shape. To make our analysis robust against imperfect knowledge of the instrumental noise, we challenge this crucial assumption and assume that the single-link interferometric noises have an arbitrary and unknown spectrum. We investigate possible ways of separating instrumental and GW contributions by using realistic LISA data simulations with time-varying arms and second-generation time-delay interferometry. By fitting a generic spline model to the interferometer noise and a power-law template to the signal, we can detect GW stochastic backgrounds up to energy density levels comparable with fixed-shape models. We also demonstrate that we can probe a region of the GW background parameter space that today's detectors cannot access.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Bayle, Dr Jean-Baptiste
Authors: Baghi, Q., Karnesis, N., Bayle, J.-B., Besançon, M., and Inchauspé, H.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Journal of Cosmology and Astroparticle Physics
Publisher:IOP Publishing
ISSN:1475-7516
ISSN (Online):1475-7516
Published Online:26 April 2023
Copyright Holders:Copyright © 2023 The Authors
First Published:First published in Journal of Cosmology and Astroparticle Physics 2023(4): 66
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
309859LISA GROUND SEGMENTGraham WoanUK Space Agency (UKSPACE)ST/W002825/1P&S - Physics & Astronomy