Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematics

Summary: Gravitational-wave observations of binary black holes allow new tests of general relativity (GR) to be performed on strong, dynamical gravitational fields. These tests require accurate waveform models of the gravitational-wave signal; otherwise waveform errors can erroneously suggest eviden...

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Main Authors: Christopher J. Moore, Eliot Finch, Riccardo Buscicchio, Davide Gerosa
Format: Article
Language:English
Published: Elsevier 2021-06-01
Series:iScience
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2589004221005459
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author Christopher J. Moore
Eliot Finch
Riccardo Buscicchio
Davide Gerosa
author_facet Christopher J. Moore
Eliot Finch
Riccardo Buscicchio
Davide Gerosa
author_sort Christopher J. Moore
collection DOAJ
description Summary: Gravitational-wave observations of binary black holes allow new tests of general relativity (GR) to be performed on strong, dynamical gravitational fields. These tests require accurate waveform models of the gravitational-wave signal; otherwise waveform errors can erroneously suggest evidence for new physics. Existing waveforms are generally thought to be accurate enough for current observations, and each of the events observed to date appears to be individually consistent with GR. In the near future, with larger gravitational-wave catalogs, it will be possible to perform more stringent tests of gravity by analyzing large numbers of events together. However, there is a danger that waveform errors can accumulate among events: even if the waveform model is accurate enough for each individual event, it can still yield erroneous evidence for new physics when applied to a large catalog. This paper presents a simple linearized analysis, in the style of a Fisher matrix calculation that reveals the conditions under which the apparent evidence for new physics due to waveform errors grows as the catalog size increases. We estimate that, in the worst-case scenario, evidence for a deviation from GR might appear in some tests using a catalog containing as few as 10–30 events above a signal-to-noise ratio of 20. This is close to the size of current catalogs and highlights the need for caution when performing these sorts of experiments.
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spelling doaj.art-89281c3de62745e7a3bb67c590551e352022-12-21T19:24:18ZengElsevieriScience2589-00422021-06-01246102577Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematicsChristopher J. Moore0Eliot Finch1Riccardo Buscicchio2Davide Gerosa3School of Physics and Astronomy & Institute for Gravitational Wave Astronomy, University of Birmingham, Birmingham B15 2TT, UK; Corresponding authorSchool of Physics and Astronomy & Institute for Gravitational Wave Astronomy, University of Birmingham, Birmingham B15 2TT, UKSchool of Physics and Astronomy & Institute for Gravitational Wave Astronomy, University of Birmingham, Birmingham B15 2TT, UKSchool of Physics and Astronomy & Institute for Gravitational Wave Astronomy, University of Birmingham, Birmingham B15 2TT, UKSummary: Gravitational-wave observations of binary black holes allow new tests of general relativity (GR) to be performed on strong, dynamical gravitational fields. These tests require accurate waveform models of the gravitational-wave signal; otherwise waveform errors can erroneously suggest evidence for new physics. Existing waveforms are generally thought to be accurate enough for current observations, and each of the events observed to date appears to be individually consistent with GR. In the near future, with larger gravitational-wave catalogs, it will be possible to perform more stringent tests of gravity by analyzing large numbers of events together. However, there is a danger that waveform errors can accumulate among events: even if the waveform model is accurate enough for each individual event, it can still yield erroneous evidence for new physics when applied to a large catalog. This paper presents a simple linearized analysis, in the style of a Fisher matrix calculation that reveals the conditions under which the apparent evidence for new physics due to waveform errors grows as the catalog size increases. We estimate that, in the worst-case scenario, evidence for a deviation from GR might appear in some tests using a catalog containing as few as 10–30 events above a signal-to-noise ratio of 20. This is close to the size of current catalogs and highlights the need for caution when performing these sorts of experiments.http://www.sciencedirect.com/science/article/pii/S2589004221005459observational astronomyastrophysics methodsgravitational waves
spellingShingle Christopher J. Moore
Eliot Finch
Riccardo Buscicchio
Davide Gerosa
Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematics
iScience
observational astronomy
astrophysics methods
gravitational waves
title Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematics
title_full Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematics
title_fullStr Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematics
title_full_unstemmed Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematics
title_short Testing general relativity with gravitational-wave catalogs: The insidious nature of waveform systematics
title_sort testing general relativity with gravitational wave catalogs the insidious nature of waveform systematics
topic observational astronomy
astrophysics methods
gravitational waves
url http://www.sciencedirect.com/science/article/pii/S2589004221005459
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