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Kurkela A, Rajagopal K, Steinhorst R. Astrophysical Equation-of-State Constraints on the Color-Superconducting Gap. PHYSICAL REVIEW LETTERS 2024; 132:262701. [PMID: 38996309 DOI: 10.1103/physrevlett.132.262701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/29/2024] [Accepted: 05/17/2024] [Indexed: 07/14/2024]
Abstract
We demonstrate that astrophysical constraints on the dense-matter equation of state place an upper bound on the color-superconducting gap in dense matter above the transition from nuclear matter to quark matter. Pairing effects in the color-flavor locked quark matter phase increase the pressure at high density, and if this effect is sufficiently large then the requirements of causality and mechanical stability make it impossible to reach such a pressure in a way that is consistent with what is known at lower densities. The intermediate-density equation of state is inferred by considering extensions of chiral effective field theory to neutron star densities, and conditioning these using current astrophysical observations of neutron star radius, maximum mass, and tidal deformability (PSR J0348+0432, PSR J1624-2230, PSR J0740+6620, GW170817). At baryon number chemical potential μ=2.6 GeV we find a 95% upper limit on the color-flavor locked pairing gap Δ of 457 MeV using overly conservative assumptions and 216 MeV with more reasonable assumptions. This constraint may be strengthened by future astrophysical measurements as well as by future advances in high-density QCD calculations.
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Chaudhary SS, Toivonen A, Waratkar G, Mo G, Chatterjee D, Antier S, Brockill P, Coughlin MW, Essick R, Ghosh S, Morisaki S, Baral P, Baylor A, Adhikari N, Brady P, Cabourn Davies G, Dal Canton T, Cavaglia M, Creighton J, Choudhary S, Chu YK, Clearwater P, Davis L, Dent T, Drago M, Ewing B, Godwin P, Guo W, Hanna C, Huxford R, Harry I, Katsavounidis E, Kovalam M, Li AK, Magee R, Marx E, Meacher D, Messick C, Morice-Atkinson X, Pace A, De Pietri R, Piotrzkowski B, Roy S, Sachdev S, Singer LP, Singh D, Szczepanczyk M, Tang D, Trevor M, Tsukada L, Villa-Ortega V, Wen L, Wysocki D. Low-latency gravitational wave alert products and their performance at the time of the fourth LIGO-Virgo-KAGRA observing run. Proc Natl Acad Sci U S A 2024; 121:e2316474121. [PMID: 38652749 PMCID: PMC11067028 DOI: 10.1073/pnas.2316474121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 03/16/2024] [Indexed: 04/25/2024] Open
Abstract
Multimessenger searches for binary neutron star (BNS) and neutron star-black hole (NSBH) mergers are currently one of the most exciting areas of astronomy. The search for joint electromagnetic and neutrino counterparts to gravitational wave (GW)s has resumed with ALIGO's, AdVirgo's and KAGRA's fourth observing run (O4). To support this effort, public semiautomated data products are sent in near real-time and include localization and source properties to guide complementary observations. In preparation for O4, we have conducted a study using a simulated population of compact binaries and a mock data challenge (MDC) in the form of a real-time replay to optimize and profile the software infrastructure and scientific deliverables. End-toend performance was tested, including data ingestion, running online search pipelines, performing annotations, and issuing alerts to the astrophysics community. We present an overview of the low-latency infrastructure and the performance of the data products that are now being released during O4 based on the MDC. We report the expected median latency for the preliminary alert of full bandwidth searches (29.5 s) and show consistency and accuracy of released data products using the MDC. We report the expected median latency for triggers from early warning searches (-3.1 s), which are new in O4 and target neutron star mergers during inspiral phase. This paper provides a performance overview for LIGO-Virgo-KAGRA (LVK) low-latency alert infrastructure and data products using theMDCand serves as a useful reference for the interpretation of O4 detections.
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Affiliation(s)
- Sushant Sharma Chaudhary
- Institute of Multi-messenger Astrophysics and Cosmology, Missouri University of Science and Technology, Rolla, MO65409
| | - Andrew Toivonen
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN55455
| | | | - Geoffrey Mo
- MIT Kavli Institute for Astrophysics, Massachusetts Institute of Technology, Cambridge, MA02139
- MIT Laser Interferometer Gravitational-Wave Observatory Laboratory, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Deep Chatterjee
- MIT Kavli Institute for Astrophysics, Massachusetts Institute of Technology, Cambridge, MA02139
- MIT Laser Interferometer Gravitational-Wave Observatory Laboratory, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Sarah Antier
- Artemis, Observatoire de la Côte d’Azur, Université Côte d’Azur, Nice06304, France
| | - Patrick Brockill
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | - Michael W. Coughlin
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN55455
| | - Reed Essick
- Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ONM5S 3H8, Canada
- Department of Physics, University of Toronto, Toronto, ONM5S 1A7, Canada
- David A. Dunlap Department of Astronomy, University of Toronto, Toronto, ONM5S 3H4, Canada
| | - Shaon Ghosh
- Department of Physics and Astronomy, Montclair State University, NJ07043
| | - Soichiro Morisaki
- Institute for Cosmic Ray Research, The University of Tokyo, Chiba277-8582, Japan
| | - Pratyusava Baral
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | - Amanda Baylor
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | - Naresh Adhikari
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | - Patrick Brady
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | | | - Tito Dal Canton
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay91405, France
| | - Marco Cavaglia
- Institute of Multi-messenger Astrophysics and Cosmology, Missouri University of Science and Technology, Rolla, MO65409
| | | | - Sunil Choudhary
- Australian Research Council Centre of Excellence for Gravitational Wave Discovery, HawthornVIC3122, Australia
- Department of Physics, University of Western Australia, CrawleyWA6009, Australia
| | - Yu-Kuang Chu
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | - Patrick Clearwater
- Australian Research Council Centre of Excellence for Gravitational Wave Discovery, HawthornVIC3122, Australia
- Department of Physics, University of Western Australia, CrawleyWA6009, Australia
| | - Luke Davis
- Australian Research Council Centre of Excellence for Gravitational Wave Discovery, HawthornVIC3122, Australia
- Department of Physics, University of Western Australia, CrawleyWA6009, Australia
| | - Thomas Dent
- Instituto Galego de Física de Altas Enerxías, Universidade de Santiago de Compostela, 15705Santiago de Compostela, Spain
| | - Marco Drago
- Universitá di Roma La Sapienza and INFN, Sezione di Roma, RomaI-00133, Italy
| | - Becca Ewing
- Department of Physics, The Pennsylvania State University, University Park, PA16802
- Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA16802
| | - Patrick Godwin
- Laser Interferometer Gravitational-Wave Observatory (LIGO) Laboratory, California Institute of Technology, Pasadena, CA91125
| | - Weichangfeng Guo
- Australian Research Council Centre of Excellence for Gravitational Wave Discovery, HawthornVIC3122, Australia
- Department of Physics, University of Western Australia, CrawleyWA6009, Australia
| | - Chad Hanna
- Department of Physics, The Pennsylvania State University, University Park, PA16802
- Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA16802
- Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA16802
- Institute for Computational and Data Sciences, The Pennsylvania State University, University Park, PA16802
| | - Rachael Huxford
- Department of Physics, The Pennsylvania State University, University Park, PA16802
- Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA16802
| | - Ian Harry
- University of Portsmouth, PortsmouthPO1 3FX, United Kingdom
| | - Erik Katsavounidis
- MIT Kavli Institute for Astrophysics, Massachusetts Institute of Technology, Cambridge, MA02139
- MIT Laser Interferometer Gravitational-Wave Observatory Laboratory, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Manoj Kovalam
- Australian Research Council Centre of Excellence for Gravitational Wave Discovery, HawthornVIC3122, Australia
- Department of Physics, University of Western Australia, CrawleyWA6009, Australia
| | - Alvin K.Y. Li
- Laser Interferometer Gravitational-Wave Observatory (LIGO) Laboratory, California Institute of Technology, Pasadena, CA91125
| | - Ryan Magee
- Laser Interferometer Gravitational-Wave Observatory (LIGO) Laboratory, California Institute of Technology, Pasadena, CA91125
| | - Ethan Marx
- MIT Kavli Institute for Astrophysics, Massachusetts Institute of Technology, Cambridge, MA02139
- MIT Laser Interferometer Gravitational-Wave Observatory Laboratory, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Duncan Meacher
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | - Cody Messick
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | | | - Alexander Pace
- Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA16802
| | - Roberto De Pietri
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Universitá di Parma, ParmaI-43124, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca, Gruppo Collegato di Parma, ParmaI-43124, Italy
| | - Brandon Piotrzkowski
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
| | - Soumen Roy
- Nikhef, Amsterdam1098 XG, The Netherlands
- Institute for Gravitational and Subatomic Physics, Utrecht University, Utrecht3584 CC, The Netherlands
| | - Surabhi Sachdev
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
- School of Physics, Georgia Institute of Technology, Atlanta, GW30332
| | - Leo P. Singer
- Astrophysics Science Division, NASA Goddard Space Flight Center, Code 661, Greenbelt, MD20771
- Joint Space-Science Institute, University of Maryland, College Park, MD20742
| | - Divya Singh
- Department of Physics, The Pennsylvania State University, University Park, PA16802
- Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA16802
| | | | - Daniel Tang
- Australian Research Council Centre of Excellence for Gravitational Wave Discovery, HawthornVIC3122, Australia
- Department of Physics, University of Western Australia, CrawleyWA6009, Australia
| | - Max Trevor
- Department of Physics, University of Maryland, College Park, MD20742
| | - Leo Tsukada
- Department of Physics, The Pennsylvania State University, University Park, PA16802
- Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA16802
| | - Verónica Villa-Ortega
- Instituto Galego de Física de Altas Enerxías, Universidade de Santiago de Compostela, 15705Santiago de Compostela, Spain
| | - Linqing Wen
- Australian Research Council Centre of Excellence for Gravitational Wave Discovery, HawthornVIC3122, Australia
- Department of Physics, University of Western Australia, CrawleyWA6009, Australia
| | - Daniel Wysocki
- Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI53201
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Pang PTH, Dietrich T, Coughlin MW, Bulla M, Tews I, Almualla M, Barna T, Kiendrebeogo RW, Kunert N, Mansingh G, Reed B, Sravan N, Toivonen A, Antier S, VandenBerg RO, Heinzel J, Nedora V, Salehi P, Sharma R, Somasundaram R, Van Den Broeck C. An updated nuclear-physics and multi-messenger astrophysics framework for binary neutron star mergers. Nat Commun 2023; 14:8352. [PMID: 38123551 PMCID: PMC10733434 DOI: 10.1038/s41467-023-43932-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023] Open
Abstract
The multi-messenger detection of the gravitational-wave signal GW170817, the corresponding kilonova AT2017gfo and the short gamma-ray burst GRB170817A, as well as the observed afterglow has delivered a scientific breakthrough. For an accurate interpretation of all these different messengers, one requires robust theoretical models that describe the emitted gravitational-wave, the electromagnetic emission, and dense matter reliably. In addition, one needs efficient and accurate computational tools to ensure a correct cross-correlation between the models and the observational data. For this purpose, we have developed the Nuclear-physics and Multi-Messenger Astrophysics framework NMMA. The code allows incorporation of nuclear-physics constraints at low densities as well as X-ray and radio observations of isolated neutron stars. In previous works, the NMMA code has allowed us to constrain the equation of state of supranuclear dense matter, to measure the Hubble constant, and to compare dense-matter physics probed in neutron-star mergers and in heavy-ion collisions, and to classify electromagnetic observations and perform model selection. Here, we show an extension of the NMMA code as a first attempt of analyzing the gravitational-wave signal, the kilonova, and the gamma-ray burst afterglow simultaneously. Incorporating all available information, we estimate the radius of a 1.4M⊙ neutron star to be [Formula: see text] km.
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Affiliation(s)
- Peter T H Pang
- Nikhef, Science Park 105, 1098 XG, Amsterdam, The Netherlands
- Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, Princetonplein 1, 3584 CC, Utrecht, The Netherlands
| | - Tim Dietrich
- Institut für Physik und Astronomie, Universität Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, 14476, Potsdam, Germany.
- Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, 14476, Potsdam, Germany.
| | - Michael W Coughlin
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Mattia Bulla
- The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, SE-106 91, Stockholm, Sweden
- Department of Physics and Earth Science, University of Ferrara, Via Saragat 1, I-44122, Ferrara, Italy
- INFN, Sezione di Ferrara, Via Saragat 1, I-44122, Ferrara, Italy
- INAF, Osservatorio Astronomico d'Abruzzo, Via Mentore Maggini snc, 64100, Teramo, Italy
| | - Ingo Tews
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Mouza Almualla
- Department of Physics, American University of Sharjah, PO Box 26666, Sharjah, UAE
| | - Tyler Barna
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Ramodgwendé Weizmann Kiendrebeogo
- Laboratoire de Physique et de Chimie de l'Environnement, Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso
- Observatoire de la Côte d'Azur, Université Côte d'Azur, CNRS, 96 Boulevard de l'Observatoire, F06304, Nice Cedex 4, France
| | - Nina Kunert
- Institut für Physik und Astronomie, Universität Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, 14476, Potsdam, Germany
| | - Gargi Mansingh
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Physics, American University, Washington, DC, 20016, USA
| | - Brandon Reed
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Physics and Astronomy, University of Minnesota-Duluth, Duluth, MN, 55812, USA
| | - Niharika Sravan
- Department of Physics, Drexel University, Philadelphia, PA, 19104, USA
| | - Andrew Toivonen
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Sarah Antier
- Observatoire de la Côte d'Azur, Université Côte d'Azur, CNRS, 96 Boulevard de l'Observatoire, F06304, Nice Cedex 4, France
| | - Robert O VandenBerg
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jack Heinzel
- Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA
| | - Vsevolod Nedora
- Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Pouyan Salehi
- Institut für Physik und Astronomie, Universität Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, 14476, Potsdam, Germany
| | - Ritwik Sharma
- Department of Physics, Deshbandhu College, University of Delhi, New Delhi, India
| | - Rahul Somasundaram
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Université Lyon, Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, F-69622, Villeurbanne, France
- Department of Physics, Syracuse University, Syracuse, NY, 13244, USA
| | - Chris Van Den Broeck
- Nikhef, Science Park 105, 1098 XG, Amsterdam, The Netherlands
- Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, Princetonplein 1, 3584 CC, Utrecht, The Netherlands
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Annala E, Gorda T, Hirvonen J, Komoltsev O, Kurkela A, Nättilä J, Vuorinen A. Strongly interacting matter exhibits deconfined behavior in massive neutron stars. Nat Commun 2023; 14:8451. [PMID: 38114461 PMCID: PMC10730725 DOI: 10.1038/s41467-023-44051-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/28/2023] [Indexed: 12/21/2023] Open
Abstract
Neutron-star cores contain matter at the highest densities in our Universe. This highly compressed matter may undergo a phase transition where nuclear matter melts into deconfined quark matter, liberating its constituent quarks and gluons. Quark matter exhibits an approximate conformal symmetry, predicting a specific form for its equation of state (EoS), but it is currently unknown whether the transition takes place inside at least some physical neutron stars. Here, we quantify this likelihood by combining information from astrophysical observations and theoretical calculations. Using Bayesian inference, we demonstrate that in the cores of maximally massive stars, the EoS is consistent with quark matter. We do this by establishing approximate conformal symmetry restoration with high credence at the highest densities probed and demonstrating that the number of active degrees of freedom is consistent with deconfined matter. The remaining likelihood is observed to correspond to EoSs exhibiting phase-transition-like behavior, treated as arbitrarily rapid crossovers in our framework.
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Affiliation(s)
- Eemeli Annala
- Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, University of Helsinki, Finland
| | - Tyler Gorda
- Technische Universität Darmstadt, Department of Physics, 64289, Darmstadt, Germany.
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany.
| | - Joonas Hirvonen
- Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, University of Helsinki, Finland.
| | - Oleg Komoltsev
- Faculty of Science and Technology, University of Stavanger, 4036, Stavanger, Norway.
| | - Aleksi Kurkela
- Faculty of Science and Technology, University of Stavanger, 4036, Stavanger, Norway.
| | - Joonas Nättilä
- Center for Computational Astrophysics, Flatiron Institute, 162 Fifth Avenue, New York, NY, 10010, USA.
- Physics Department and Columbia Astrophysics Laboratory, Columbia University, 538 West 120th Street, New York, NY, 10027, USA.
| | - Aleksi Vuorinen
- Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, University of Helsinki, Finland.
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Gorda T, Paatelainen R, Säppi S, Seppänen K. Equation of State of Cold Quark Matter to O(α_{s}^{3}lnα_{s}). PHYSICAL REVIEW LETTERS 2023; 131:181902. [PMID: 37977603 DOI: 10.1103/physrevlett.131.181902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/29/2023] [Accepted: 10/05/2023] [Indexed: 11/19/2023]
Abstract
Accurately understanding the equation of state (EOS) of high-density, zero-temperature quark matter plays an essential role in constraining the behavior of dense strongly interacting matter inside the cores of neutron stars. In this Letter, we study the weak-coupling expansion of the EOS of cold quark matter and derive the complete, gauge-invariant contributions from the long-wavelength, dynamically screened gluonic sector at next-to-next-to-next-to-leading order (N3LO) in the strong coupling constant α_{s}. This elevates the EOS result to the O(α_{s}^{3}lnα_{s}) level, leaving only one unknown constant from the unscreened sector at N3LO, and places it on par with its high-temperature counterpart from 2003.
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Affiliation(s)
- Tyler Gorda
- Technische Universität Darmstadt, Department of Physics, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - Risto Paatelainen
- Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, Finland
| | - Saga Säppi
- TUM Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
- Excellence Cluster ORIGINS, Boltzmannstrasse 2, 85748 Garching, Germany
| | - Kaapo Seppänen
- Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, Finland
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6
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Raithel CA, Most ER. Degeneracy in the Inference of Phase Transitions in the Neutron Star Equation of State from Gravitational Wave Data. PHYSICAL REVIEW LETTERS 2023; 130:201403. [PMID: 37267559 DOI: 10.1103/physrevlett.130.201403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/19/2022] [Accepted: 04/10/2023] [Indexed: 06/04/2023]
Abstract
Gravitational wave (GW) detections of binary neutron star inspirals will be crucial for constraining the dense matter equation of state (EOS). We demonstrate a new degeneracy in the mapping from tidal deformability data to the EOS, which occurs for models with strong phase transitions. We find that there exists a new family of EOS with phase transitions that set in at different densities and that predict neutron star radii that differ by up to ∼500 m but that produce nearly identical tidal deformabilities for all neutron star masses. Next-generation GW detectors and advances in nuclear theory may be needed to resolve this degeneracy.
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Affiliation(s)
- Carolyn A Raithel
- School of Natural Sciences, Institute for Advanced Study, 1 Einstein Drive, Princeton, New Jersey 08540, USA; Princeton Center for Theoretical Science, Jadwin Hall, Princeton University, Princeton, New Jersey 08544, USA and Princeton Gravity Initiative, Jadwin Hall, Princeton University, Princeton, New Jersey 08544, USA
| | - Elias R Most
- School of Natural Sciences, Institute for Advanced Study, 1 Einstein Drive, Princeton, New Jersey 08540, USA; Princeton Center for Theoretical Science, Jadwin Hall, Princeton University, Princeton, New Jersey 08544, USA and Princeton Gravity Initiative, Jadwin Hall, Princeton University, Princeton, New Jersey 08544, USA
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7
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Han MZ, Huang YJ, Tang SP, Fan YZ. Plausible presence of new state in neutron stars with masses above 0.98M TOV. Sci Bull (Beijing) 2023; 68:913-919. [PMID: 37080849 DOI: 10.1016/j.scib.2023.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 04/22/2023]
Abstract
We investigate the neutron star (NS) equation of state (EOS) by incorporating multi-messenger data of GW170817, PSR J0030 + 0451, PSR J0740 + 6620, and state-of-the-art theoretical progresses, including the information from chiral effective field theory (χEFT) and perturbative quantum chromodynamics (pQCD) calculation. Taking advantage of the various structures sampling by a single-layer feed-forward neural network model embedded in the Bayesian nonparametric inference, the structure of NS matter's sound speed cs is explored in a model-agnostic way. It is found that a peak structure is common in the cs2 posterior, locating at 2.4-4.8ρsat (nuclear saturation density) and cs2 exceeds c2/3 at 90% credibility. The non-monotonic behavior suggests evidence of the state deviating from the hadronic matter inside the very massive NSs. Assuming the new/exotic state is featured as it is softer than typical hadronic models or even with hyperons, we find that a sizable (⩾10-3M⊙) exotic core, likely made of quark matter, is plausible for the NS with a gravitational mass above about 0.98MTOV, where MTOV represents the maximum gravitational mass of a non-rotating cold NS. The inferred MTOV=2.18-0.13+0.27M⊙ (90% credibility) is well consistent with the value of 2.17-0.12+0.15M⊙ estimated independently with GW170817/GRB 170817A/AT2017gfo assuming a temporary supramassive NS remnant formed after the merger. PSR J0740 + 6620, the most massive NS detected so far, may host a sizable exotic core with a probability of ≈0.36.
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Affiliation(s)
- Ming-Zhe Han
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China; School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, China
| | - Yong-Jia Huang
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China; School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, China; RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), RIKEN, Wako 351-0198, Japan
| | - Shao-Peng Tang
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
| | - Yi-Zhong Fan
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China; School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, China.
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8
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Keller J, Hebeler K, Schwenk A. Nuclear Equation of State for Arbitrary Proton Fraction and Temperature Based on Chiral Effective Field Theory and a Gaussian Process Emulator. PHYSICAL REVIEW LETTERS 2023; 130:072701. [PMID: 36867798 DOI: 10.1103/physrevlett.130.072701] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 12/09/2022] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
We calculate the equation of state of asymmetric nuclear matter at finite temperature based on chiral effective field theory interactions to next-to-next-to-next-to-leading order. Our results assess the theoretical uncertainties from the many-body calculation and the chiral expansion. Using a Gaussian process emulator for the free energy, we derive the thermodynamic properties of matter through consistent derivatives and use the Gaussian process to access arbitrary proton fraction and temperature. This enables a first nonparametric calculation of the equation of state in beta equilibrium, and of the speed of sound and the symmetry energy at finite temperature. Moreover, our results show that the thermal part of the pressure decreases with increasing densities.
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Affiliation(s)
- J Keller
- Technische Universität Darmstadt, Department of Physics, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - K Hebeler
- Technische Universität Darmstadt, Department of Physics, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - A Schwenk
- Technische Universität Darmstadt, Department of Physics, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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9
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Soma S, Wang L, Shi S, Stöcker H, Zhou K. A physics-based neural network reconstruction of the dense matter equation of state from neutron star observables. EPJ WEB OF CONFERENCES 2023. [DOI: 10.1051/epjconf/202327606007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023] Open
Abstract
We introduce a novel technique that utilizes a physics-driven deep learning method to reconstruct the dense matter equation of state from neutron star observables, particularly the masses and radii. The proposed framework involves two neural networks: one to optimize the EoS using Automatic Differentiation in the unsupervised learning scheme; and a pre-trained network to solve the Tolman–Oppenheimer–Volkoff (TOV) equations. The gradient-based optimization process incorporates a Bayesian picture into the proposed framework. The reconstructed EoS is proven to be consistent with the results from conventional methods. Furthermore, the resulting tidal deformation is in agreement with the limits obtained from the gravitational wave event, GW170817.
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10
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Kölsch M, Dietrich T, Ujevic M, Brügmann B. Investigating the mass-ratio dependence of the prompt-collapse threshold with numerical-relativity simulations. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.044026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Biswas B, Datta S. Constraining neutron star properties with a new equation of state insensitive approach. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.043012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Ujevic M, Rashti A, Gieg H, Tichy W, Dietrich T. High-accuracy high-mass-ratio simulations for binary neutron stars and their comparison to existing waveform models. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.023029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Perego A, Logoteta D, Radice D, Bernuzzi S, Kashyap R, Das A, Padamata S, Prakash A. Probing the Incompressibility of Nuclear Matter at Ultrahigh Density through the Prompt Collapse of Asymmetric Neutron Star Binaries. PHYSICAL REVIEW LETTERS 2022; 129:032701. [PMID: 35905358 DOI: 10.1103/physrevlett.129.032701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/16/2022] [Accepted: 06/06/2022] [Indexed: 06/15/2023]
Abstract
Using 250 neutron star merger simulations with microphysics, we explore for the first time the role of nuclear incompressibility in the prompt collapse threshold for binaries with different mass ratios. We demonstrate that observations of prompt collapse thresholds, either from binaries with two different mass ratios or with one mass ratio but combined with the knowledge of the maximum neutron star mass or compactness, will constrain the incompressibility at the maximum neutron star density K_{max} to within tens of percent. This otherwise inaccessible measure of K_{max} can potentially reveal the presence of hyperons or quarks inside neutron stars.
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Affiliation(s)
- Albino Perego
- Dipartimento di Fisica, Università di Trento, Via Sommarive 14, 38123 Trento, Italy
- INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Via Sommarive 14, I-38123 Trento, Italy
| | - Domenico Logoteta
- Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
- INFN, Sezione di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - David Radice
- Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Sebastiano Bernuzzi
- Theoretisch-Physikalisches Institut, Friedrich-Schiller Universität Jena, 07743 Jena, Germany
| | - Rahul Kashyap
- Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Abhishek Das
- Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Surendra Padamata
- Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Aviral Prakash
- Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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14
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Incorporating a Radiative Hydrodynamics Scheme in the Numerical-Relativity Code BAM. UNIVERSE 2022. [DOI: 10.3390/universe8070370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To study binary neutron star systems and to interpret observational data such as gravitational-wave and kilonova signals, one needs an accurate description of the processes that take place during the final stages of the coalescence, for example, through numerical-relativity simulations. In this work, we present an updated version of the numerical-relativity code BAM in order to incorporate nuclear-theory-based equations of state and a simple description of neutrino interactions through a neutrino leakage scheme. Different test simulations, for stars undergoing a neutrino-induced gravitational collapse and for binary neutron stars systems, validate our new implementation. For the binary neutron stars systems, we show that we can evolve stably and accurately distinct microphysical models employing the different equations of state: SFHo, DD2, and the hyperonic BHBΛϕ. Overall, our test simulations have good agreement with those reported in the literature.
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15
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Huth S, Pang PTH, Tews I, Dietrich T, Le Fèvre A, Schwenk A, Trautmann W, Agarwal K, Bulla M, Coughlin MW, Van Den Broeck C. Constraining neutron-star matter with microscopic and macroscopic collisions. Nature 2022; 606:276-280. [PMID: 35676430 PMCID: PMC9177417 DOI: 10.1038/s41586-022-04750-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 04/11/2022] [Indexed: 11/16/2022]
Abstract
Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not probed only in astrophysical observations, but also in terrestrial heavy-ion collision experiments. Here we use Bayesian inference to combine data from astrophysical multi-messenger observations of neutron stars1-9 and from heavy-ion collisions of gold nuclei at relativistic energies10,11 with microscopic nuclear theory calculations12-17 to improve our understanding of dense matter. We find that the inclusion of heavy-ion collision data indicates an increase in the pressure in dense matter relative to previous analyses, shifting neutron-star radii towards larger values, consistent with recent observations by the Neutron Star Interior Composition Explorer mission5-8,18. Our findings show that constraints from heavy-ion collision experiments show a remarkable consistency with multi-messenger observations and provide complementary information on nuclear matter at intermediate densities. This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars.
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Affiliation(s)
- Sabrina Huth
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany.
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
| | - Peter T H Pang
- Nikhef, Amsterdam, The Netherlands.
- Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, Utrecht, The Netherlands.
| | - Ingo Tews
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Tim Dietrich
- Institut für Physik und Astronomie, Universität Potsdam, Potsdam, Germany
- Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam, Germany
| | - Arnaud Le Fèvre
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Achim Schwenk
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
| | | | - Kshitij Agarwal
- Physikalisches Institut, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Mattia Bulla
- The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, Stockholm, Sweden
| | - Michael W Coughlin
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Chris Van Den Broeck
- Nikhef, Amsterdam, The Netherlands
- Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, Utrecht, The Netherlands
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16
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Komoltsev O, Kurkela A. How Perturbative QCD Constrains the Equation of State at Neutron-Star Densities. PHYSICAL REVIEW LETTERS 2022; 128:202701. [PMID: 35657894 DOI: 10.1103/physrevlett.128.202701] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/14/2022] [Accepted: 04/25/2022] [Indexed: 06/15/2023]
Abstract
We demonstrate in a general and analytic way how high-density information about the equation of state (EOS) of strongly interacting matter obtained using perturbative quantum chromodynamics constrains the same EOS at densities reachable in physical neutron stars. Our approach is based on utilizing the full information of the thermodynamic potentials at the high-density limit together with thermodynamic stability and causality. This requires considering the pressure as a function of chemical potential p(μ) instead of the commonly used pressure as a function of energy density p(ε). The results can be used to propagate the perturbative quantum chromodynamics calculations reliable around 40n_{s} to lower densities in the most conservative way possible. We constrain the EOS starting from only a few times the nuclear saturation density n≳2.2n_{s}, and at n=5n_{s} we exclude at least 65% of otherwise allowed area in the ε-p plane. This provides information complementary to astrophysical observations that should be taken into account in any complete statistical inference study of the EOS. These purely theoretical results are independent of astrophysical neutron-star input, and hence, they can also be used to test theories of modified gravity and beyond the standard model physics in neutron stars.
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Affiliation(s)
- Oleg Komoltsev
- Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
| | - Aleksi Kurkela
- Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
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17
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Pacilio C, Maselli A, Fasano M, Pani P. Ranking Love Numbers for the Neutron Star Equation of State: The Need for Third-Generation Detectors. PHYSICAL REVIEW LETTERS 2022; 128:101101. [PMID: 35333071 DOI: 10.1103/physrevlett.128.101101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 01/22/2022] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
Gravitational-wave measurements of the tidal deformability in neutron-star binary coalescences can be used to infer the still unknown equation of state (EOS) of dense matter above the nuclear saturation density. By employing a Bayesian-ranking test, we quantify the ability of current and future gravitational-wave observations to discriminate among families of nuclear-physics based EOS which differ in particle content and ab initio microscopic calculations. While the constraining power of GW170817 is limited, we show that even twenty coalescences detected by LIGO-Virgo at design sensitivity are not enough to discriminate between EOS with similar softness but distinct microphysics. However, just a single detection with a third-generation detector such as the Einstein Telescope or Cosmic Explorer will rule out several families of EOS with very strong statistical significance and can discriminate among models which feature similar softness, hence, constraining the properties of nuclear matter to unprecedented levels.
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Affiliation(s)
- Costantino Pacilio
- Dipartimento di Fisica, "Sapienza" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
- INFN, Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy
| | - Andrea Maselli
- Gran Sasso Science Institute (GSSI), I-67100 L'Aquila, Italy
- INFN, Laboratori Nazionali del Gran Sasso, I-67100 Assergi, Italy
| | - Margherita Fasano
- Dipartimento di Fisica, "Sapienza" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Paolo Pani
- Dipartimento di Fisica, "Sapienza" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
- INFN, Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy
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18
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Li A. Can we distinguish quark stars from neutron stars with measurements of global properties? EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202226004001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The phase state of the dense stellar matter is an exciting topic in the area of nuclear astrophysics. It may be probed by observed properties of neutron stars from, for example, the currently operating satellites (NICER, Neutron star Interior Composition Explorer) and the gravitational-wave laser interferometers (Advanced LIGO, Virgo, and KAGRA). Based on our recent constrained parameter spaces of the equation of states of neutron stars and quark stars from LIGO/Virgo and NICER, we discuss the important role of an even-accurate determination of the stellar radius for distinguishing possible quark stars from neutron stars and our understanding of the QCD phase transition at finite density.
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19
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Abstract
The neutron star properties are generally determined by the equation of state of β-equilibrated dense matter. In this work, we consider the interaction of fermionic dark matter (DM) particles with nucleons via Higgs exchange and investigate the effect on the neutron star properties with the relativistic mean-field model equation of state coupled with DM. We deduce that DM significantly affects the neutron star properties, such as considerably reducing the maximum mass of the star, which depends on the percentage of the DM considered inside the neutron star. The tidal Love numbers both for electric and magnetic cases and surficial Love numbers are also studied for DM admixed NS. We observed that the magnitude of tidal and surficial Love numbers increases with a greater DM percentage. Further, we present post-Newtonian tidal corrections to gravitational waves decreased by increasing the DM percentage. The DM effect on the GW signal is significant during the late inspiral and merger stages of binary evolution for GW frequencies >500 Hz.
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20
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Gorda T. Improving the cold quark-matter pressure via soft interactions at N3LO. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202225805004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The propagation of long-wavelength gluons through a dense QCD medium at high baryon chemical potential μB is qualitatively modified by the effects of screening, arising from scatterings off the high-momentum quarks in the medium. This same screening phenomenon also impacts gluons occurring in loop corrections to the pressure of cold quark matter, leading to contributions from the parametric scale αs1/2μB, starting at next-to-next-to-leading order (N2LO) in the strong coupling constant αs. At next-to-next-to-next-to-leading order (N3LO), interactions between these long-wavelength gluonic modes contribute to the pressure. These interaction corrections have recently been computed in Ref [1, 2], and the inclusion of these interactions slightly improves the convergence of the equation of state of cold quark matter. In these proceedings, we present these results and provide details summarizing how this lengthy calculation was performed.
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21
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Mallick R. Gravitational wave signatures of phase transition from hadronic to quark matter in isolated neutron stars and binaries. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202227407002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The fundamental constituent of matter at high temperature and density has intrigued physicists for quite some time. Recent results from heavy-ion colliders have enriched the Quantum Chromodynamics phase diagram at high temperatures and low baryon density. However, the phase at low temperatures and finite (mostly intermediate) baryon density remain unexplored. Theoretical Quantum Chromodynamics calculation predicts phase transition from hadronic matter to quark matter at such densities. Presently, the best laboratories available to probe such densities lie at the core of neutron stars. Recent results of how such phase transition signatures can be probed using gravitational waves both in isolated neutron stars and neutron star in binaries. The isolated neutron star would probe the very low-temperature regime, whereas neutron stars in binaries would probe finite baryon density in the intermediate temperature regime. We would also discuss whether the gravitational wave signature of such phase transition is unique and the detector specification needed to detect such signals.
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22
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Mathews GJ, Kedia A, Kim HI, Suh IS. Neutron Star Mergers and the Quark Matter Equation of State. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202227401013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
As neutron stars merge they can approach very high nuclear density. Here, we summarized recent results for the evolution and gravitational wave emission from binary-neutron star mergers using a a variety of nuclear equations of state with and without a crossover transition to quark matter. We discuss how the late time gravitational wave emission from binary neutron star mergers may possibly reveal the existence of a crossover transition to quark matter.
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23
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Uniqueness of the Inflationary Higgs Scalar for Neutron Stars and Failure of Non-Inflationary Approximations. Symmetry (Basel) 2021. [DOI: 10.3390/sym14010032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neutron stars are perfect candidates to investigate the effects of a modified gravity theory, since the curvature effects are significant and more importantly, potentially testable. In most cases studied in the literature in the context of massive scalar-tensor theories, inflationary models were examined. The most important of scalar-tensor models is the Higgs model, which, depending on the values of the scalar field, can be approximated by different scalar potentials, one of which is the inflationary. Since it is not certain how large the values of the scalar field will be at the near vicinity and inside a neutron star, in this work we will answer the question, which potential form of the Higgs model is more appropriate in order for it to describe consistently a static neutron star. As we will show numerically, the non-inflationary Higgs potential, which is valid for certain values of the scalar field in the Jordan frame, leads to extremely large maximum neutron star masses; however, the model is not self-consistent, because the scalar field approximation used for the derivation of the potential, is violated both at the center and at the surface of the star. These results shows the uniqueness of the inflationary Higgs potential, since it is the only approximation for the Higgs model, that provides self-consistent results.
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24
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Phase Conversions in Neutron Stars: Implications for Stellar Stability and Gravitational Wave Astrophysics. UNIVERSE 2021. [DOI: 10.3390/universe7120493] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We review the properties of hybrid stars with a quark matter core and a hadronic mantle, focusing on the role of key micro-physical properties such as the quark/hadron surface and curvature tensions and the conversion speed at the interface between both phases. We summarize the results of works that have determined the surface and curvature tensions from microscopic calculations. If these quantities are large enough, mixed phases are energetically suppressed and the quark core would be separated from the hadronic mantle by a sharp interface. If the conversion speed at the interface is slow, a new class of dynamically stable hybrid objects is possible. Densities tens of times larger than the nuclear saturation density can be attained at the center of these objects. We discuss possible formation mechanisms for the new class of hybrid stars and smoking guns for their observational identification.
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25
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Gorda T, Kurkela A, Paatelainen R, Säppi S, Vuorinen A. Soft Interactions in Cold Quark Matter. PHYSICAL REVIEW LETTERS 2021; 127:162003. [PMID: 34723602 DOI: 10.1103/physrevlett.127.162003] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/12/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Accurate knowledge of the thermodynamic properties of zero-temperature, high-density quark matter plays an integral role in attempts to constrain the behavior of the dense QCD matter found inside neutron-star cores, irrespective of the phase realized inside the stars. In this Letter, we consider the weak-coupling expansion of the dense QCD equation of state and compute the next-to-next-to-next-to-leading-order contribution arising from the non-Abelian interactions among long-wavelength, dynamically screened gluonic fields. Accounting for these interactions requires an all-loop resummation, which can be performed using hard-thermal-loop (HTL) kinematic approximations. Concretely, we perform a full two-loop computation using the HTL effective theory, valid for the long-wavelength, or soft, modes. We find that the soft sector is well behaved within cold quark matter, contrary to the case encountered at high temperatures, and find that the new contribution decreases the renormalization-scale dependence of the equation of state at high density.
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Affiliation(s)
- Tyler Gorda
- Technische Universität Darmstadt, Department of Physics, D-64289 Darmstadt, Germany
- Helmholtz Research Academy for FAIR, D-64289 Darmstadt, Germany
| | - Aleksi Kurkela
- Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
| | - Risto Paatelainen
- Helsinki Institute of Physics and Department of Physics, FI-00014 University of Helsinki, Finland
| | - Saga Säppi
- Helsinki Institute of Physics and Department of Physics, FI-00014 University of Helsinki, Finland
- European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*) and Fondazione Bruno Kessler, Strada delle Tabarelle 286, I-38123, Villazzano (TN), Italy
| | - Aleksi Vuorinen
- Helsinki Institute of Physics and Department of Physics, FI-00014 University of Helsinki, Finland
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26
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Castro G, Gualtieri L, Pani P. Hidden symmetry between rotational tidal Love numbers of spinning neutron stars. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.104.044052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Yagi K, Stepniczka M. Neutron stars in scalar-tensor theories: Analytic scalar charges and universal relations. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.104.044017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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Abstract
In this paper, an investigation of the role of nuclear saturation parameters on f-mode oscillations in neutron stars is performed within the Cowling approximation. It is found that the uncertainty in the effective nucleon mass plays a dominant role in controlling the f-mode frequencies. The effect of the uncertainties in saturation parameters on previously-proposed empirical relations of the frequencies with astrophysical observables relevant for asteroseismology are also investigated. These results can serve as an important tool for constraining the nuclear parameter space and understand the behaviour of dense nuclear matter from the future detection of f-modes.
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29
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Sun TT, Zheng ZY, Chen H, Burgio GF, Schulze HJ. Equation of state and radial oscillations of neutron stars. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.103.103003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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30
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Sedda MA, Berry CPL, Jani K, Amaro-Seoane P, Auclair P, Baird J, Baker T, Berti E, Breivik K, Caprini C, Chen X, Doneva D, Ezquiaga JM, Ford KES, Katz ML, Kolkowitz S, McKernan B, Mueller G, Nardini G, Pikovski I, Rajendran S, Sesana A, Shao L, Tamanini N, Warburton N, Witek H, Wong K, Zevin M. The missing link in gravitational-wave astronomy: A summary of discoveries waiting in the decihertz range. EXPERIMENTAL ASTRONOMY 2021; 51:1427-1440. [PMID: 34720416 PMCID: PMC8536607 DOI: 10.1007/s10686-021-09713-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 02/09/2021] [Indexed: 06/13/2023]
Abstract
Since 2015 the gravitational-wave observations of LIGO and Virgo have transformed our understanding of compact-object binaries. In the years to come, ground-based gravitational-wave observatories such as LIGO, Virgo, and their successors will increase in sensitivity, discovering thousands of stellar-mass binaries. In the 2030s, the space-based LISA will provide gravitational-wave observations of massive black holes binaries. Between the ∼ 10 -103 Hz band of ground-based observatories and the ∼ 1 0 - 4 -10- 1 Hz band of LISA lies the uncharted decihertz gravitational-wave band. We propose a Decihertz Observatory to study this frequency range, and to complement observations made by other detectors. Decihertz observatories are well suited to observation of intermediate-mass ( ∼ 1 0 2 -104 M ⊙) black holes; they will be able to detect stellar-mass binaries days to years before they merge, providing early warning of nearby binary neutron star mergers and measurements of the eccentricity of binary black holes, and they will enable new tests of general relativity and the Standard Model of particle physics. Here we summarise how a Decihertz Observatory could provide unique insights into how black holes form and evolve across cosmic time, improve prospects for both multimessenger astronomy and multiband gravitational-wave astronomy, and enable new probes of gravity, particle physics and cosmology.
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Affiliation(s)
- Manuel Arca Sedda
- Astronomisches Rechen-Institut, Zentrüm für Astronomie, Universität Heidelberg, Mönchofstr. 12-14, Heidelberg, Germany
| | - Christopher P. L. Berry
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 USA
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - Karan Jani
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37212 USA
| | - Pau Amaro-Seoane
- Universitat Politècnica de València, IGIC, Valencia, Spain
- Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, 100871 China
- Institute of Applied Mathematics, Academy of Mathematics and Systems Science, CAS, Beijing, 100190 China
- Zentrum für Astronomie und Astrophysik, TU Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - Pierre Auclair
- Laboratoire Astroparticule et Cosmologie, CNRS UMR 7164, Université Paris-Diderot, 10 rue Alice Domon et Léonie Duquet, 75013 Paris, France
| | - Jonathon Baird
- High Energy Physics Group, Physics Department, Imperial College London, Blackett Laboratory, Prince Consort Road, London, SW7 2BW UK
| | - Tessa Baker
- School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London, E1 4NS UK
| | - Emanuele Berti
- Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 USA
| | - Katelyn Breivik
- Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7 Canada
| | - Chiara Caprini
- Laboratoire Astroparticule et Cosmologie, CNRS UMR 7164, Université Paris-Diderot, 10 rue Alice Domon et Léonie Duquet, 75013 Paris, France
| | - Xian Chen
- Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, 100871 China
- Astronomy Department, School of Physics, Peking University, Beijing, 100871 China
| | - Daniela Doneva
- Theoretical Astrophysics, Eberhard Karls University of Tübingen, Tübingen, 72076 Germany
| | - Jose M. Ezquiaga
- Kavli Institute for Cosmological Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637 USA
| | - K. E. Saavik Ford
- City University of New York-BMCC, Chambers St, New York, NY 10007 USA
- Department of Astrophysics, American Museum of Natural History, New York, NY 10028 USA
| | - Michael L. Katz
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 USA
| | - Shimon Kolkowitz
- Department of Physics, University of Wisconsin – Madison, Madison, WI 53706 USA
| | - Barry McKernan
- City University of New York-BMCC, Chambers St, New York, NY 10007 USA
- Department of Astrophysics, American Museum of Natural History, New York, NY 10028 USA
| | - Guido Mueller
- Department of Physics, University of Florida, PO Box 118440, Gainesville, Florida 32611 USA
| | - Germano Nardini
- Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
| | - Igor Pikovski
- Department of Physics, Stevens Institute of Technology, Hoboken, NJ 07030 USA
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Surjeet Rajendran
- Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 USA
| | - Alberto Sesana
- Università di Milano Bicocca, Dipartimento di Fisica G. Occhialini, Piazza della Scienza 3, I-20126 Milano, Italy
| | - Lijing Shao
- Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, 100871 China
- National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 China
| | - Nicola Tamanini
- Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Niels Warburton
- School of Mathematics and Statistics, University College Dublin, Belfield, Dublin 4 Ireland
| | - Helvi Witek
- Department of Physics, King’s College London, Strand, London WC2R 2LS UK
| | - Kaze Wong
- Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 USA
| | - Michael Zevin
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 USA
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Abstract
The I-Love-Q relations are approximate equation-of-state independent relations that connect the moment of inertia, the spin-induced quadrupole moment, and the tidal deformability of neutron stars. In this paper, we study the I-Love-Q relations for superfluid neutron stars for a general relativistic two-fluid model: one fluid being the neutron superfluid and the other a conglomerate of all charged components. We study to what extent the two-fluid dynamics might affect the robustness of the I-Love-Q relations by using a simple two-component polytropic model and a relativistic mean field model with entrainment for the equation-of-state. Our results depend crucially on the spin ratio Ωn/Ωp between the angular velocities of the neutron superfluid and the normal component. We find that the I-Love-Q relations can still be satisfied to high accuracy for superfluid neutron stars as long as the two fluids are nearly co-rotating Ωn/Ωp≈1. However, the deviations from the I-Love-Q relations increase as the spin ratio deviates from unity. In particular, the deviation of the Q-Love relation can be as large as O(10%) if Ωn/Ωp differ from unity by a few tens of percent. As Ωn/Ωp≈1 is expected for realistic neutron stars, our results suggest that the two-fluid dynamics should not affect the accuracy of any gravitational waveform models for neutron star binaries that employ the relation to connect the spin-induced quadrupole moment and the tidal deformability.
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Le Tiec A, Casals M. Spinning Black Holes Fall in Love. PHYSICAL REVIEW LETTERS 2021; 126:131102. [PMID: 33861128 DOI: 10.1103/physrevlett.126.131102] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/18/2020] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
The open question of whether a black hole can become tidally deformed by an external gravitational field has profound implications for fundamental physics, astrophysics, and gravitational-wave astronomy. Love tensors characterize the tidal deformability of compact objects such as astrophysical (Kerr) black holes under an external static tidal field. We prove that all Love tensors vanish identically for a Kerr black hole in the nonspinning limit or for an axisymmetric tidal perturbation. In contrast to this result, we show that Love tensors are generically nonzero for a spinning black hole. Specifically, to linear order in the Kerr black hole spin and the weak perturbing tidal field, we compute in closed form the Love tensors that couple the mass-type and current-type quadrupole moments to the electric-type and magnetic-type quadrupolar tidal fields. For a dimensionless spin ∼0.1, the nonvanishing quadrupolar Love tensors are ∼2×10^{-3}, thus showing that black holes are particularly "rigid" compact objects.
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Affiliation(s)
- Alexandre Le Tiec
- Laboratoire Univers et Théories, Observatoire de Paris, CNRS, Université PSL, Université de Paris, 92190 Meudon, France
- Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, CEP 22290-180, Brazil
| | - Marc Casals
- Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, CEP 22290-180, Brazil
- School of Mathematics and Statistics, University College Dublin, Belfield, Dublin 4, Ireland
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34
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35
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Ma S, Yu H, Chen Y. Detecting resonant tidal excitations of Rossby modes in coalescing neutron-star binaries with third-generation gravitational-wave detectors. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.103.063020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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36
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Abstract
Background: We analyze several constraints on the nuclear equation of state (EOS) currently available from neutron star (NS) observations and laboratory experiments and study the existence of possible correlations among properties of nuclear matter at saturation density with NS observables. Methods: We use a set of different models that include several phenomenological EOSs based on Skyrme and relativistic mean field models as well as microscopic calculations based on different many-body approaches, i.e., the (Dirac–)Brueckner–Hartree–Fock theories, Quantum Monte Carlo techniques, and the variational method. Results: We find that almost all the models considered are compatible with the laboratory constraints of the nuclear matter properties as well as with the largest NS mass observed up to now, 2.14−0.09+0.10M⊙ for the object PSR J0740+6620, and with the upper limit of the maximum mass of about 2.3–2.5M⊙ deduced from the analysis of the GW170817 NS merger event. Conclusion: Our study shows that whereas no correlation exists between the tidal deformability and the value of the nuclear symmetry energy at saturation for any value of the NS mass, very weak correlations seem to exist with the derivative of the nuclear symmetry energy and with the nuclear incompressibility.
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Benitez E, Weller J, Guedes V, Chirenti C, Miller MC. Investigating the I-Love-Q and
w
-mode universal relations using piecewise polytropes. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.103.023007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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39
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Ruiz M, Paschalidis V, Tsokaros A, Shapiro SL. Black hole-neutron star coalescence: Effects of the neutron star spin on jet launching and dynamical ejecta mass. PHYSICAL REVIEW. D. (2016) 2020; 102:124077. [PMID: 34595362 PMCID: PMC8477222 DOI: 10.1103/physrevd.102.124077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Black hole-neutron star (BHNS) mergers are thought to be sources of gravitational waves (GWs) with coincident electromagnetic (EM) counterparts. To further probe whether these systems are viable progenitors of short gamma-ray bursts (SGRBs) and kilonovas, and how one may use (the lack of) EM counterparts associated with LIGO/Virgo candidate BHNS GW events to sharpen parameter estimation, we study the impact of neutron star spin in BHNS mergers. Using dynamical spacetime magnetohydrodynamic simulations of BHNSs initially on a quasicircular orbit, we survey configurations that differ in the BH spin (a BH/M BH = 0 and 0.75), the NS spin (a NS/M NS = -0.17, 0, 0.23, and 0.33), and the binary mass ratio (q = M BH:M NS = 3:1 and 5:1). The general trend we find is that increasing the NS prograde spin increases both the rest mass of the accretion disk onto the remnant black hole, and the rest mass of dynamically ejected matter. By a time Δt ~ 3500-5500M ~ 88-138(M NS/1.4 M ⊙) ms after the peak gravitational-wave amplitude, a magnetically driven jet is launched only for q = 3:1 regardless of the initial NS spin. The lifetime of the jets [Δt ~ 0.5-0.8(M NS/1.4 M ⊙) s] and their outgoing Poynting luminosity [L Poyn ~ 1051.5±0.5 erg/s] are consistent with typical SGRBs' luminosities and expectations from the Blandford-Znajek mechanism. By the time we terminate our simulations, we do not observe either an outflow or a large-scale magnetic-field collimation for the other systems we consider. The mass range of dynamically ejected matter is 10-4.5-10-2(M NS/1.4 M ⊙) M ⊙, which can power kilonovas with peak bolometric luminosities L knova ~ 1040-1041.4 erg/s with rise times ≲6.5 h and potentially detectable by the LSST.
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Affiliation(s)
- Milton Ruiz
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Vasileios Paschalidis
- Departments of Astronomy and Physics, University of Arizona, Tucson, Arizona 85719, USA
| | - Antonios Tsokaros
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Stuart L Shapiro
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Astronomy and NCSA, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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41
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Neutron Star Properties: Quantifying the Effect of the Crust–Core Matching Procedure. UNIVERSE 2020. [DOI: 10.3390/universe6110220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The impact of the equation of state (EoS) crust-core matching procedure on neutron star (NS) properties is analyzed within a meta-modeling approach. Using a Taylor expansion to parametrize the core equation of state (EoS) and the SLy4 crust EoS, we create two distinct EoS datasets employing two matching procedures. Each EoS describes cold NS matter in a β equilibrium that is thermodynamically stable and causal. It is shown that the crust-core matching procedure affects not only the crust-core transition but also the nuclear matter parameter space of the core EoS, and thus the most probable nuclear matter properties. An uncertainty of as much as 5% (8%) on the determination of low mass NS radii (tidal deformability) is attributed to the complete matching procedure, including the effect on core EoS. By restricting the analysis, imposing that the same set of core EoS is retained in both matching procedures, the uncertainty on the NS radius drops to 3.5% and below 1.5% for 1.9M⊙. Moreover, under these conditions, the crust-core matching procedure has a strong impact on the Love number k2, of almost 20% for 1.0M⊙ stars and 7% for 1.9M⊙ stars, but it shows a very small impact on the tidal deformability Λ, below 1%.
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42
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Comparison between the Thomas–Fermi and Hartree–Fock–Bogoliubov Methods in the Inner Crust of a Neutron Star: The Role of Pairing Correlations. UNIVERSE 2020. [DOI: 10.3390/universe6110206] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigated the role of a pairing correlation in the chemical composition of the inner crust of a neutron star with the extended Thomas–Fermi method, using the Strutinsky integral correction. We compare our results with the fully self-consistent Hartree–Fock–Bogoliubov approach, showing that the resulting discrepancy, apart from the very low density region, is compatible with the typical accuracy we can achieve with standard mean-field methods.
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Zhu Z, Li A, Rezzolla L. Tidal deformability and gravitational-wave phase evolution of magnetized compact-star binaries. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.102.084058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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45
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Most ER, Papenfort LJ, Weih LR, Rezzolla L. A lower bound on the maximum mass if the secondary in GW190814 was once a rapidly spinning neutron star. ACTA ACUST UNITED AC 2020. [DOI: 10.1093/mnrasl/slaa168] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
ABSTRACT
The recent detection of GW190814 featured the merger of a binary with a primary having a mass of $\sim 23\, \mathrm{ M}_{\odot }$ and a secondary with a mass of $\sim 2.6\, \mathrm{ M}_{\odot }$. While the primary was most likely a black hole, the secondary could be interpreted as either the lightest black hole or the most massive neutron star ever observed, but also as the indication of a novel class of exotic compact objects. We here argue that although the secondary in GW190814 is most likely a black hole at merger, it needs not be an ab-initio black hole nor an exotic object. Rather, based on our current understanding of the nuclear-matter equation of state, it can be a rapidly rotating neutron star that collapsed to a rotating black hole at some point before merger. Using universal relations connecting the masses and spins of uniformly rotating neutron stars, we estimate the spin, $0.49_{-0.05}^{+0.08} \lesssim \chi \lesssim 0.68_{-0.05}^{+0.11}$, of the secondary – a quantity not constrained so far by the detection – and a novel strict lower bound on the maximum mass, $M_{_{\mathrm{TOV}}}\gt 2.08^{+0.04}_{-0.04}\, \, \mathrm{ M}_{\odot }$ and an optimal bound of $M_{_{\mathrm{TOV}}}\gt 2.15^{+0.04}_{-0.04}\, \, \mathrm{ M}_{\odot }$, of non-rotating neutron stars, consistent with recent observations of a very massive pulsar. The new lower bound also remains valid even in the less likely scenario in which the secondary neutron star never collapsed to a black hole.
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Affiliation(s)
- Elias R Most
- Institut für Theoretische Physik, Goethe Universität, Max-von-Laue-Str 1, D-60438 Frankfurt am Main, Germany
| | - L Jens Papenfort
- Institut für Theoretische Physik, Goethe Universität, Max-von-Laue-Str 1, D-60438 Frankfurt am Main, Germany
| | - Lukas R Weih
- Institut für Theoretische Physik, Goethe Universität, Max-von-Laue-Str 1, D-60438 Frankfurt am Main, Germany
| | - Luciano Rezzolla
- Institut für Theoretische Physik, Goethe Universität, Max-von-Laue-Str 1, D-60438 Frankfurt am Main, Germany
- School of Mathematics, Trinity College, Dublin 2, Ireland
- Helmholtz Research Academy Hesse for FAIR, Max-von-Laue-Str 12, D-60438 Frankfurt am Main, Germany
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46
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Abstract
Background. We investigate possible correlations between neutron star observables and properties of atomic nuclei. In particular, we explore how the tidal deformability of a 1.4 solar mass neutron star, M1.4, and the neutron-skin thickness of 48Ca and 208Pb are related to the stellar radius and the stiffness of the symmetry energy. Methods. We examine a large set of nuclear equations of state based on phenomenological models (Skyrme, NLWM, DDM) and ab initio theoretical methods (BBG, Dirac–Brueckner, Variational, Quantum Monte Carlo). Results: We find strong correlations between tidal deformability and NS radius, whereas a weaker correlation does exist with the stiffness of the symmetry energy. Regarding the neutron-skin thickness, weak correlations appear both with the stiffness of the symmetry energy, and the radius of a M1.4. Our results show that whereas the considered EoS are compatible with the largest masses observed up to now, only five microscopic models and four Skyrme forces are simultaneously compatible with the present constraints on L and the PREX experimental data on the 208Pb neutron-skin thickness. We find that all the NLWM and DDM models and the majority of the Skyrme forces are excluded by these two experimental constraints, and that the analysis of the data collected by the NICER mission excludes most of the NLWM considered. Conclusion. The tidal deformability of a M1.4 and the neutron-skin thickness of atomic nuclei show some degree of correlation with nuclear and astrophysical observables, which however depends on the ensemble of adopted EoS.
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47
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Abstract
We study the cooling of isolated neutron stars with particular regard to the importance of nuclear pairing gaps. A microscopic nuclear equation of state derived in the Brueckner-Hartree-Fock approach is used together with compatible neutron and proton pairing gaps. We then study the effect of modifying the gaps on the final deduced neutron star mass distributions. We find that a consistent description of all current cooling data can be achieved and a reasonable neutron star mass distribution can be predicted employing the (slightly reduced by about 40%) proton 1S0 Bardeen-Cooper-Schrieffer (BCS) gaps and no neutron 3P2 pairing.
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48
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Abstract
Magnetohydrodynamic (MHD) turbulence in neutron star (NS) merger remnants can impact their evolution and multi-messenger signatures, complicating the interpretation of present and future observations. Due to the high Reynolds numbers and the large computational costs of numerical relativity simulations, resolving all the relevant scales of the turbulence will be impossible for the foreseeable future. Here, we adopt a method to include subgrid-scale turbulence in moderate resolution simulations by extending the large-eddy simulation (LES) method to general relativity (GR). We calibrate our subgrid turbulence model with results from very-high-resolution GRMHD simulations, and we use it to perform NS merger simulations and study the impact of turbulence. We find that turbulence has a quantitative, but not qualitative, impact on the evolution of NS merger remnants, on their gravitational wave signatures, and on the outflows generated in binary NS mergers. Our approach provides a viable path to quantify uncertainties due to turbulence in NS mergers.
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49
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Ma S, Yu H, Chen Y. Excitation of
f
-modes during mergers of spinning binary neutron star. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.101.123020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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50
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Was GW170817 a Canonical Neutron Star Merger? Bayesian Analysis with a Third Family of Compact Stars. UNIVERSE 2020. [DOI: 10.3390/universe6060081] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We investigate the possibility that GW170817 was not the merger of two conventional neutron stars (NS), but involved at least one if not two hybrid stars with a quark matter core that might even belong to a third family of compact stars. To this end, we develop a Bayesian analysis method for selecting the most probable equation of state (EoS) under a set of constraints from compact star physics, which now also include the tidal deformability from GW170817 and the first result for the mass and radius determination for PSR J0030+0451 by the NICER Collaboration. We apply this method for the first time to a two-parameter family of hybrid EoS based on the DD2 model with nucleonic excluded volume for hadronic matter and the color superconducting generalized nlNJL model for quark matter. The model has a variable onset density for deconfinement and can mimic the effects of pasta phases with the possibility of producing a third family of hybrid stars in the mass-radius diagram. The main findings of this study are that: (1) the presence of multiple configurations for a given mass (twins or even triples) corresponds to a set of disconnected lines in the Λ 1 – Λ 2 diagram of tidal deformabilities for binary mergers, so that merger events from the same mass range may result in a probability landscape with different peak positions; (2) the Bayesian analysis with the above observational constraints favors an early onset of the deconfinement transition, at masses of M onset ≤ 0.8 M ⊙ with an M–R relationship that in the range of observed neutron star masses is almost indistinguishable from that of a soft hadronic Akmal, Pandharipande, and Ravenhall (APR) EoS; (3) a few, yet fictitious measurements of the NICER experiment two times more accurate than the present value and a different mass and radius that would change the posterior likelihood so that hybrid EoS with a phase transition onset in the range M onset = 1.1–1.6 M ⊙ would be favored.
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