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Implicit correlations within phenomenological parametric models of the neutron star equation of state

Legred, Isaac and Chatziioannou, Katerina and Essick, Reed and Landry, Philippe (2022) Implicit correlations within phenomenological parametric models of the neutron star equation of state. Physical Review D, 105 (4). Art. No. 043016. ISSN 2470-0010. doi:10.1103/physrevd.105.043016.

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The rapid increase in the number and precision of astrophysical probes of neutron stars in recent years allows for the inference of their equation of state. Observations target different macroscopic properties of neutron stars which vary from star to star, such as mass and radius, but the equation of state allows for a common description of all neutron stars. To connect these observations and infer the properties of dense matter and neutron stars simultaneously, models for the equation of state are introduced. Parametric models rely on carefully engineered functional forms that reproduce a large array of realistic equations of state. Such models benefit from their simplicity but are limited because any finite-parameter model cannot accurately approximate all possible equations of state. Nonparametric methods overcome this by increasing model freedom at the cost of increased complexity. In this study, we compare common parametric and nonparametric models, quantify the limitations of the former, and study the impact of modeling on our current understanding of high-density physics. We show that parametric models impose strongly model-dependent, and sometimes opaque, correlations between density scales. Such interdensity correlations result in tighter constraints that are unsupported by data and can lead to biased inference of the equation of state and of individual neutron star properties.

Item Type:Article
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URLURL TypeDescription Paper
Legred, Isaac0000-0002-9523-9617
Chatziioannou, Katerina0000-0002-5833-413X
Landry, Philippe0000-0002-8457-1964
Additional Information:© 2022 American Physical Society. (Received 24 January 2022; accepted 31 January 2022; published 24 February 2022) We thank Les Wade for useful discussions on the implementation of the spectal model in lalsuite. R. E. thanks the Canadian Institute for Advanced Research (CIFAR) for support. Research at Perimeter Institute is supported in part by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Colleges and Universities. P. L. is supported by the Natural Sciences and Engineering Research Council of Canada (NSERC). This research has made use of data, software, and/or web tools obtained from the Gravitational Wave Open Science Center [73], a service of LIGO Laboratory, the LIGO Scientific Collaboration, and the Virgo Collaboration. Virgo is funded by the French Centre National de Recherche Scientifique (CNRS), the Italian Istituto Nazionale della Fisica Nucleare (INFN), and the Dutch Nikhef, with contributions by Polish and Hungarian institutes. This material is based upon work supported by NSF’s LIGO Laboratory which is a major facility fully funded by the National Science Foundation. The authors are grateful for computational resources provided by the LIGO Laboratory and supported by National Science Foundation Grants No. PHY-0757058 and No. PHY-0823459.
Group:Astronomy Department, LIGO
Funding AgencyGrant Number
Canadian Institute for Advanced Research (CIFAR)UNSPECIFIED
Department of Innovation, Science and Economic Development (Canada)UNSPECIFIED
Ontario Ministry of Colleges and UniversitiesUNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Istituto Nazionale di Fisica Nucleare (INFN)UNSPECIFIED
Issue or Number:4
Record Number:CaltechAUTHORS:20220225-724672000
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113614
Deposited By: George Porter
Deposited On:25 Feb 2022 22:39
Last Modified:25 Jul 2022 23:14

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