1
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Figueroa DG, Pieroni M, Ricciardone A, Simakachorn P. Cosmological Background Interpretation of Pulsar Timing Array Data. PHYSICAL REVIEW LETTERS 2024; 132:171002. [PMID: 38728738 DOI: 10.1103/physrevlett.132.171002] [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: 11/09/2023] [Accepted: 03/25/2024] [Indexed: 05/12/2024]
Abstract
We discuss the interpretation of the detected signal by pulsar timing array (PTA) observations as a gravitational wave background of cosmological origin. We combine NANOGrav 15-years and EPTA-DR2new datasets and confront them against backgrounds from supermassive black hole binaries (SMBHBs), and cosmological signals from inflation, cosmic (super)strings, first-order phase transitions, Gaussian and non-Gaussian large scalar fluctuations, and audible axions. We find that scalar-induced, and to a lesser extent audible axion and cosmic superstring signals, provide a better fit than SMBHBs. These results depend, however, on modeling assumptions, so further data and analysis are needed to reach robust conclusions. Independently of the signal origin, the data strongly constrain the parameter space of cosmological signals, for example, setting an upper bound on primordial non-Gaussianity at PTA scales as |f_{nl}|≲2.34 at 95% C.L.
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Affiliation(s)
- Daniel G Figueroa
- Instituto de Física Corpuscular, Consejo Superior de Investigaciones Científicas and Universitat de València, 46980, Valencia, Spain
| | - Mauro Pieroni
- Theoretical Physics Department, CERN, 1211 Geneva 23, Switzerland
| | - Angelo Ricciardone
- Dipartimento di Fisica "E. Fermi", Università di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica e Astronomia "G. Galilei", Università degli Studi di Padova, via Marzolo 8, I-35131 Padova, Italy
| | - Peera Simakachorn
- Instituto de Física Corpuscular, Consejo Superior de Investigaciones Científicas and Universitat de València, 46980, Valencia, Spain
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2
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Franciolini G, Iovino AJ, Vaskonen V, Veermäe H. Recent Gravitational Wave Observation by Pulsar Timing Arrays and Primordial Black Holes: The Importance of Non-Gaussianities. PHYSICAL REVIEW LETTERS 2023; 131:201401. [PMID: 38039467 DOI: 10.1103/physrevlett.131.201401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/19/2023] [Indexed: 12/03/2023]
Abstract
We study whether the signal seen by pulsar timing arrays (PTAs) may originate from gravitational waves (GWs) induced by large primordial perturbations. Such perturbations may be accompanied by a sizable primordial black hole (PBH) abundance. We improve existing analyses and show that PBH overproduction disfavors Gaussian scenarios for scalar-induced GWs at 2σ and single-field inflationary scenarios, accounting for non-Gaussianity, at 3σ as the explanation of the most constraining NANOGrav 15-year data. This tension can be relaxed in models where non-Gaussianities suppress the PBH abundance. On the flip side, the PTA data does not constrain the abundance of PBHs.
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Affiliation(s)
- Gabriele Franciolini
- Dipartimento di Fisica, "Sapienza" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
- INFN sezione di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Antonio Junior Iovino
- Dipartimento di Fisica, "Sapienza" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
- INFN sezione di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
- National Institute of Chemical Physics and Biophysics, Rävala 10, Tallinn, Estonia
| | - Ville Vaskonen
- National Institute of Chemical Physics and Biophysics, Rävala 10, Tallinn, Estonia
- Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, Via Marzolo 8, 35131 Padova, Italy
- INFN sezione di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - Hardi Veermäe
- National Institute of Chemical Physics and Biophysics, Rävala 10, Tallinn, Estonia
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3
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Pi S, Sasaki M. Logarithmic Duality of the Curvature Perturbation. PHYSICAL REVIEW LETTERS 2023; 131:011002. [PMID: 37478432 DOI: 10.1103/physrevlett.131.011002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 04/17/2023] [Accepted: 06/02/2023] [Indexed: 07/23/2023]
Abstract
We study the comoving curvature perturbation R in the single-field inflation models whose potential can be approximated by a piecewise quadratic potential V(φ) by using the δN formalism. We find a general formula for R(δφ,δπ), consisting of a sum of logarithmic functions of the field perturbation δφ and the velocity perturbation δπ at the point of interest, as well as of δπ_{*} at the boundaries of each quadratic piece, which are functions of (δφ,δπ) through the equation of motion. Each logarithmic expression has an equivalent dual expression, due to the second-order nature of the equation of motion for φ. We also clarify the condition under which R(δφ,δπ) reduces to a single logarithm, which yields either the renowned "exponential tail" of the probability distribution function of R or a Gumbel-distribution-like tail.
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Affiliation(s)
- Shi Pi
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center for High Energy Physics, Peking University, Beijing 100871, China
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - Misao Sasaki
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
- Center for Gravitational Physics and Quantum Information, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
- Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617
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4
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Lu P, Takhistov V, Fuller GM. Signatures of a High Temperature QCD Transition in the Early Universe. PHYSICAL REVIEW LETTERS 2023; 130:221002. [PMID: 37327409 DOI: 10.1103/physrevlett.130.221002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/21/2023] [Accepted: 05/02/2023] [Indexed: 06/18/2023]
Abstract
Beyond-Standard-Model extensions of QCD could result in quark and gluon confinement occurring well above at temperature around the GeV scale. These models can also alter the order of the QCD phase transition. Therefore, the enhanced production of primordial black holes (PBHs) that can accompany the change in relativistic degrees of freedom at the QCD transition could favor the production of PBHs with mass scales smaller than the Standard Model QCD horizon scale. Consequently, and unlike PBHs associated with a standard GeV-scale QCD transition, such PBHs can account for all the dark matter abundance in the unconstrained asteroid-mass window. This links beyond-Standard-Model modifications of QCD physics over a broad range of unexplored temperature regimes (around 10-10^{3} TeV) with microlensing surveys searching for PBHs. Additionally, we discuss implications of these models for gravitational wave experiments. We show that a first-order QCD phase transition at around 7 TeV is consistent with the Subaru Hyper-Suprime Cam candidate event, while a transition of around 70 GeV is consistent with OGLE candidate events and could also account for the claimed NANOGrav gravitational wave signal.
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Affiliation(s)
- Philip Lu
- Center for Theoretical Physics, Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Volodymyr Takhistov
- International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP, WPI), High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan
- Theory Center, Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - George M Fuller
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
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5
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Ota A, Macpherson HJ, Coulton WR. Covariant transverse-traceless projection for secondary gravitational waves. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.063521] [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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6
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Effects of a Geometrically Realized Early Dark Energy Era on the Spectrum of Primordial Gravitational Waves. Symmetry (Basel) 2022. [DOI: 10.3390/sym14061143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In this work, we investigate the effects of a geometrically generated early dark energy era on the energy spectrum of the primordial gravitational waves. The early dark energy era, which we choose to have a constant equation of state parameter w, is synergistically generated by an appropriate f(R) gravity in the presence of matter and radiation perfect fluids. As we demonstrate, the predicted signal for the energy spectrum of the f(R) primordial gravitational waves is amplified and can be detectable, for various reheating temperatures, especially for large reheating temperatures. The signal amplitude depends on the duration of the early dark energy era and on the value of the dark energy equation of state parameter, with the latter affecting more crucially the amplification. Specifically, the amplification occurs when the equation of state parameter approaches the de Sitter value w=−1. Regarding the duration of the early dark energy era, we find that the largest amplification occurs when the early dark energy era commences at temperature T=0.85 eV until T=7.8 eV. Moreover, we study a similar scenario in which amplification occurs, where the early dark energy era commences at T=0.29 eV and lasts until the temperature is increased by ΔT∼1.7 eV. The discovery of primordial gravitational waves will reveal if several symmetries in the Universe exist or not so this work is important toward revealing the primordial gravitational waves.
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7
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Spectrum of Primordial Gravitational Waves in Modified Gravities: A Short Overview. Symmetry (Basel) 2022. [DOI: 10.3390/sym14040729] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In this work, we shall exhaustively study the effects of modified gravity on the energy spectrum of the primordial gravitational waves background. S. Weinberg has also produced significant works related to the primordial gravitational waves, with the most important one being the effects of neutrinos on primordial gravitational waves. With this short review, our main aim is to gather all the necessary information for studying the effects of modified gravity on primordial gravitational waves in a concrete and quantitative way and in a single paper. After reviewing all the necessary techniques for extracting the general relativistic energy spectrum, and how to obtain, in a WKB way, the modified gravity damping or amplifying factor, we concentrate on specific forms of modified gravity of interest. The most important parameter involved for the calculation of the effects of modified gravity on the energy spectrum is the parameter aM, which we calculate for the cases of f(R,ϕ) gravity, Chern–Simons-corrected f(R,ϕ) gravity, Einstein–Gauss–Bonnet-corrected f(R,ϕ) gravity, and higher derivative extended Einstein–Gauss–Bonnet-corrected f(R,ϕ) gravity. The exact form of aM is presented explicitly for the first time in the literature. With regard to Einstein–Gauss–Bonnet-corrected f(R,ϕ) gravity, and higher derivative extended Einstein–Gauss–Bonnet-corrected f(R,ϕ) gravity theories, we focus on the case in which the gravitational wave propagating speed is equal to that of light in a vacuum. We provide expressions for aM expressed in terms of the cosmic time and in terms of the redshift, which can be used directly for the numerical calculation of the effect of modified gravity on the primordial gravitational wave energy spectrum.
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8
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Zhang F. Primordial black holes and scalar induced gravitational waves from the
E
model with a Gauss-Bonnet term. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.105.063539] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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9
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Kristiano J, Yokoyama J. Why Must Primordial Non-Gaussianity Be Very Small? PHYSICAL REVIEW LETTERS 2022; 128:061301. [PMID: 35213181 DOI: 10.1103/physrevlett.128.061301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
One-loop correction to the power spectrum in generic single-field inflation is calculated by using standard perturbation theory. Because of the enhancement inversely proportional to the observed red tilt of the spectral index of curvature perturbation, the correction turns out to be much larger than previously anticipated. As a result, the primordial non-Gaussianity must be much smaller than the current observational bound in order to warrant the validity of cosmological perturbation theory.
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Affiliation(s)
- Jason Kristiano
- Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Jun'ichi Yokoyama
- Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), WPI, UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8568, Japan
- Trans-Scale Quantum Science Institute, The University of Tokyo, Tokyo 113-0033, Japan
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10
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Romero-Rodríguez A, Martínez M, Pujolàs O, Sakellariadou M, Vaskonen V. Search for a Scalar Induced Stochastic Gravitational Wave Background in the Third LIGO-Virgo Observing Run. PHYSICAL REVIEW LETTERS 2022; 128:051301. [PMID: 35179921 DOI: 10.1103/physrevlett.128.051301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 11/30/2021] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
The formation of primordial black holes from inflationary fluctuations is accompanied by a scalar induced gravitational wave background. We perform a Bayesian search of such background in the data from Advanced LIGO and Virgo's first, second, and third observing runs, parametrizing the peak in the curvature power spectrum by a log-normal distribution. The search shows no evidence for such a background. We place 95% confidence level upper limits on the integrated power of the curvature power spectrum peak which, for a narrow width, reaches down to 0.02 at 10^{17} Mpc^{-1}. The resulting constraints are stronger than those arising from big bang nucleosynthesis or cosmic microwave background observations. In addition, we find that the constraints from LIGO and Virgo, at their design sensitivity, and from the Einstein Telescope can compete with those related to the abundance of the formed primordial black holes.
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Affiliation(s)
- Alba Romero-Rodríguez
- Institut de Física d'Altes Energies (IFAE), Barcelona Institute of Science and Technology, E-08193 Barcelona, Spain
| | - Mario Martínez
- Institut de Física d'Altes Energies (IFAE), Barcelona Institute of Science and Technology, E-08193 Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), E-08010 Barcelona, Spain
| | - Oriol Pujolàs
- Institut de Física d'Altes Energies (IFAE), Barcelona Institute of Science and Technology, E-08193 Barcelona, Spain
| | - Mairi Sakellariadou
- Theoretical Particle Physics and Cosmology Group, Physics Department, King's College London, University of London, Strand, London WC2R 2LS, United Kingdom
| | - Ville Vaskonen
- Institut de Física d'Altes Energies (IFAE), Barcelona Institute of Science and Technology, E-08193 Barcelona, Spain
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11
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Wu YP, Pinetti E, Silk J. Cosmic Coincidences of Primordial-Black-Hole Dark Matter. PHYSICAL REVIEW LETTERS 2022; 128:031102. [PMID: 35119885 DOI: 10.1103/physrevlett.128.031102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
If primordial black holes (PBHs) contribute more than 10% of the dark matter (DM) density, their energy density today is of the same order as that of the baryons. Such a cosmic coincidence might hint at a mutual origin for the formation scenario of PBHs and the baryon asymmetry of the Universe. Baryogenesis can be triggered by a sharp transition of the rolling rate of inflaton from slow-roll to (nearly) ultraslow-roll phases that produce large curvature perturbations for PBH formation in single-field inflationary models. We show that the baryogenesis requirement drives the PBH contribution to DM, along with the inferred PBH mass range, the resulting stochastic gravitational wave background frequency window, and the associated cosmic microwave background tensor-to-scalar ratio amplitude, into potentially observable regimes.
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Affiliation(s)
- Yi-Peng Wu
- Laboratoire de Physique Théorique et Hautes Energies (LPTHE), UMR 7589 CNRS and Sorbonne Université, 4 Place Jussieu, F-75252 Paris, France
| | - Elena Pinetti
- Laboratoire de Physique Théorique et Hautes Energies (LPTHE), UMR 7589 CNRS and Sorbonne Université, 4 Place Jussieu, F-75252 Paris, France
- Dipartimento di Fisica, Universitá di Torino and INFN, Sezione di Torino, via P. Giuria 1, I-10125 Torino, Italy
- Theoretical Astrophysics Department, Fermi National Accelerator Laboratory, Batavia, Illinois, 60510, USA
| | - Joseph Silk
- Institut d'Astrophysique de Paris, UMR 7095 CNRS and Sorbonne Université, 98 bis boulevard Arago, F-75014 Paris, France
- Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
- Beecroft Institute for Particle Astrophysics and Cosmology, University of Oxford, Keble Road, Oxford OX1 3RH, United Kingdom
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12
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Liang ZC, Hu YM, Jiang Y, Cheng J, Zhang JD, Mei J. Science with the TianQin Observatory: Preliminary results on stochastic gravitational-wave background. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.105.022001] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Spanos VC, Stamou ID. Gravitational waves and primordial black holes from supersymmetric hybrid inflation. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.104.123537] [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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14
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Cai YF, Jiang J, Sasaki M, Vardanyan V, Zhou Z. Beating the Lyth Bound by Parametric Resonance during Inflation. PHYSICAL REVIEW LETTERS 2021; 127:251301. [PMID: 35029452 DOI: 10.1103/physrevlett.127.251301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/26/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
We propose a novel mechanism for enhancing primordial gravitational waves without significantly affecting the curvature perturbations produced during inflation. This is achieved due to nonlinear sourcing of resonantly amplified scalar field fluctuations. Our result is an explicit scale-dependent counterexample of the famous Lyth bound, which opens up a promising perspective of producing detectable inflationary tensor modes with low-scale inflation and a sub-Planckian field excursion. We explicitly demonstrate the testability of our mechanism with upcoming cosmic microwave background B-mode observations.
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Affiliation(s)
- Yi-Fu Cai
- Department of Astronomy, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- School of Astronomy and Space Science, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Key Laboratory for Researches in Galaxies and Cosmology, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jie Jiang
- Department of Astronomy, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- School of Astronomy and Space Science, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Key Laboratory for Researches in Galaxies and Cosmology, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Misao Sasaki
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, Chiba 277-8583, Japan
- Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
- Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan
| | - Valeri Vardanyan
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, Chiba 277-8583, Japan
| | - Zihan Zhou
- Department of Astronomy, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- School of Astronomy and Space Science, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Key Laboratory for Researches in Galaxies and Cosmology, University of Science and Technology of China, Hefei, Anhui 230026, China
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15
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Carr B, Kohri K, Sendouda Y, Yokoyama J. Constraints on primordial black holes. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2021; 84:116902. [PMID: 34874316 DOI: 10.1088/1361-6633/ac1e31] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
We update the constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over the mass range 10-5to 1050 g. Those smaller than ∼1015 g would have evaporated by now due to Hawking radiation, so their abundance at formation is constrained by the effects of evaporated particles on big bang nucleosynthesis, the cosmic microwave background (CMB), the Galactic and extragalacticγ-ray and cosmic ray backgrounds and the possible generation of stable Planck mass relics. PBHs larger than ∼1015 g are subject to a variety of constraints associated with gravitational lensing, dynamical effects, influence on large-scale structure, accretion and gravitational waves. We discuss the constraints on both the initial collapse fraction and the current fraction of the dark matter (DM) in PBHs at each mass scale but stress that many of the constraints are associated with observational or theoretical uncertainties. We also consider indirect constraints associated with the amplitude of the primordial density fluctuations, such as second-order tensor perturbations andμ-distortions arising from the effect of acoustic reheating on the CMB, if PBHs are created from the high-σpeaks of nearly Gaussian fluctuations. Finally we discuss how the constraints are modified if the PBHs have an extended mass function, this being relevant if PBHs provide some combination of the DM, the LIGO/Virgo coalescences and the seeds for cosmic structure. Even if PBHs make a small contribution to the DM, they could play an important cosmological role and provide a unique probe of the early Universe.
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Affiliation(s)
- Bernard Carr
- School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
- Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kazunori Kohri
- Theory Center, IPNS, KEK, Tsukuba, Ibaraki 305-0801, Japan
- The Graduate University for Advanced Studies (SOKENDAI), Tsukuba, Ibaraki 305-0801, Japan
- Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo, Kashiwa, Chiba 277-8568, Japan
| | - Yuuiti Sendouda
- Graduate School of Science and Technology, Hirosaki University, Hirosaki, Aomori 036-8561, Japan
| | - Jun'ichi Yokoyama
- Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo, Kashiwa, Chiba 277-8568, Japan
- Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Trans-Scale Quantum Science Institute, The University of Tokyo, Tokyo 113-0033, Japan
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17
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Abstract
We provide a review on the state-of-the-art of gravitational waves induced by primordial fluctuations, so-called induced gravitational waves. We present the intuitive physics behind induced gravitational waves and we revisit and unify the general analytical formulation. We then present general formulas in a compact form, ready to be applied. This review places emphasis on the open possibility that the primordial universe experienced a different expansion history than the often assumed radiation dominated cosmology. We hope that anyone interested in the topic will become aware of current advances in the cosmology of induced gravitational waves, as well as becoming familiar with the calculations behind.
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18
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Pujolas O, Vaskonen V, Veermäe H. Prospects for probing gravitational waves from primordial black hole binaries. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.104.083521] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Yuan C, Huang QG. A topic review on probing primordial black hole dark matter with scalar induced gravitational waves. iScience 2021; 24:102860. [PMID: 34401659 PMCID: PMC8358648 DOI: 10.1016/j.isci.2021.102860] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Primordial black holes (PBHs) might form from the collapse of over-densed regions generated by large scalar curvature perturbations in the radiation dominated era. Despite decades of various independent observations, the nature of dark matter (DM) remains highly puzzling. Recently, PBH DM have aroused interest since they provide an attracting explanation to the merger events of binary black holes discovered by LIGO/VIRGO and may play an important role on DM. During the formation of PBH, gravitational waves will be sourced by linear scalar perturbations at second-order, known as the scalar induced gravitational waves (SIGWs), which provides a new way to hunt for PBH DM. This topic review mainly focuses on the physics about SIGWs accompanying the formation of PBH DM.
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Affiliation(s)
- Chen Yuan
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Qing-Guo Huang
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009, China
- School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
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20
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Multi-Field versus Single-Field in the Supergravity Models of Inflation and Primordial Black Holes. UNIVERSE 2021. [DOI: 10.3390/universe7050115] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We review the models unifying inflation and Primordial Black Hole (PBH) formation, which are based on the modified (Starobinsky-type) supergravity. We begin with the basic (Starobinsky) inflationary model of modified gravity and its alpha-attractor-type generalizations for PBH production, and recall how all those single-field models can be embedded into the minimal supergravity. Then, we focus on the effective two-field models arising from the modified (Starobinsky-type) supergravity and compare them to the single-field models under review. Those two-field models describe double inflation whose first stage is driven by Starobinsky’s scalaron and whose second stage is driven by another scalar belonging to the supergravity multiplet. The power spectra are numerically computed, and it is found that the ultra-slow-roll regime gives rise to the enhancement (peak) in the scalar power spectrum leading to an efficient PBH formation. The resulting PBH masses and their density fraction (as part of dark matter) are found to be in agreement with cosmological observations. The PBH-induced gravitational waves, if any, are shown to be detectable by the ground-based and space-based gravitational interferometers under construction.
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Liu J, Cai RG, Guo ZK. Large Anisotropies of the Stochastic Gravitational Wave Background from Cosmic Domain Walls. PHYSICAL REVIEW LETTERS 2021; 126:141303. [PMID: 33891446 DOI: 10.1103/physrevlett.126.141303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/06/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
We investigate the stochastic gravitational wave background (SGWB) from cosmic domain walls (DWs) caused by quantum fluctuations of a light scalar field ϕ during inflation. Large-scale perturbations of ϕ lead to large-scale perturbations of DW energy density and anisotropies in the SGWB. We find that the angular power spectrum of this SGWB is scale invariant and at least of the order of 10^{-2}, which is a distinctive feature of observational interest. Since we have not detected primordial gravitational waves yet, anisotropies of the SGWB provide a nontrivial opportunity to verify the rationality of inflation and detect the energy scale of inflation, especially for low-scale inflationary models. Square kilometer array has the opportunity to detect the anisotropies of such SGWBs. The common-spectrum process observed recently by NANOGrav could also be interpreted by the SGWB from cosmic DWs.
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Affiliation(s)
- Jing Liu
- School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
| | - Rong-Gen Cai
- School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190, China
| | - Zong-Kuan Guo
- School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190, China
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Inomata K, Kawasaki M, Mukaida K, Yanagida TT. NANOGrav Results and LIGO-Virgo Primordial Black Holes in Axionlike Curvaton Models. PHYSICAL REVIEW LETTERS 2021; 126:131301. [PMID: 33861092 DOI: 10.1103/physrevlett.126.131301] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/12/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
We discuss a possible connection between the recent NANOGrav results and the primordial black holes (PBHs) for the LIGO-Virgo events. In particular, we focus on the axionlike curvaton model, which provides a sizable amount of PBHs and gravitational waves (GWs) induced by scalar perturbations around the NANOGrav frequency range. The inevitable non-Gaussianity of this model suppresses the induced GWs associated with PBHs for the LIGO-Virgo events to be compatible with the NANOGrav results. We show that the axionlike curvaton model can account for PBHs for the LIGO-Virgo events and the NANOGrav results simultaneously.
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Affiliation(s)
- Keisuke Inomata
- Kavli Institute for Cosmological Physics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Masahiro Kawasaki
- ICRR, University of Tokyo, Kashiwa 277-8582, Japan
- Kavli IPMU (WPI), UTIAS, University of Tokyo, Kashiwa 277-8583, Japan
| | - Kyohei Mukaida
- CERN, Theoretical Physics Department, CH-1211 Geneva 23, Switzerland
- DESY, Notkestraße 85, D-22607 Hamburg, Germany
| | - Tsutomu T Yanagida
- Kavli IPMU (WPI), UTIAS, University of Tokyo, Kashiwa 277-8583, Japan
- T. D. Lee Institute and School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240, China
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Ali A, Gong Y, Lu Y. Gauge transformation of scalar induced tensor perturbation during matter domination. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.103.043516] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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De Luca V, Franciolini G, Riotto A. NANOGrav Data Hints at Primordial Black Holes as Dark Matter. PHYSICAL REVIEW LETTERS 2021; 126:041303. [PMID: 33576658 DOI: 10.1103/physrevlett.126.041303] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
The NANOGrav Collaboration has recently published strong evidence for a stochastic common-spectrum process that may be interpreted as a stochastic gravitational wave background. We show that such a signal can be explained by second-order gravitational waves produced during the formation of primordial black holes from the collapse of sizeable scalar perturbations generated during inflation. This possibility has two predictions: (i) the primordial black holes may comprise the totality of the dark matter with the dominant contribution to their mass function falling in the range (10^{-15}÷10^{-11})M_{⊙} and (ii) the gravitational wave stochastic background will be seen as well by the Laser Interferometer Space Antenna experiment.
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Affiliation(s)
- V De Luca
- Département de Physique Théorique and Centre for Astroparticle Physics (CAP), Université de Genève, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - G Franciolini
- Département de Physique Théorique and Centre for Astroparticle Physics (CAP), Université de Genève, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - A Riotto
- Département de Physique Théorique and Centre for Astroparticle Physics (CAP), Université de Genève, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
- INFN, Sezione di Roma, Piazzale Aldo Moro 2, 00185, Roma, Italy
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Palma GA, Sypsas S, Zenteno C. Seeding Primordial Black Holes in Multifield Inflation. PHYSICAL REVIEW LETTERS 2020; 125:121301. [PMID: 33016764 DOI: 10.1103/physrevlett.125.121301] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/07/2020] [Indexed: 06/11/2023]
Abstract
The inflationary origin of primordial black holes (PBHs) relies on a large enhancement of the power spectrum Δ_{ζ} of the curvature fluctuation ζ at wavelengths much shorter than those of the cosmic microwave background anisotropies. This is typically achieved in models where ζ evolves without interacting significantly with additional (isocurvature) scalar degrees of freedom. However, quantum gravity inspired models are characterized by moduli spaces with highly curved geometries and a large number of scalar fields that could vigorously interact with ζ (as in the cosmological collider picture). Here we show that isocurvature fluctuations can mix with ζ inducing large enhancements of its amplitude. This occurs whenever the inflationary trajectory experiences rapid turns in the field space of the model leading to amplifications that are exponentially sensitive to the total angle swept by the turn, which induce characteristic observable signatures on Δ_{ζ}. We derive accurate analytical predictions and show that the large enhancements required for PBHs demand noncanonical kinetic terms in the action of the multifield system.
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Affiliation(s)
- Gonzalo A Palma
- Grupo de Cosmología y Astrofísica Teórica, Departamento de Física, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, Chile
| | - Spyros Sypsas
- Department of Physics, Faculty of Science, Chulalongkorn University, Phayathai Road, Bangkok 10330, Thailand
| | - Cristobal Zenteno
- Grupo de Cosmología y Astrofísica Teórica, Departamento de Física, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, Chile
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Liu L, Guo ZK, Cai RG, Kim SP. Merger rate distribution of primordial black hole binaries with electric charges. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.102.043508] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Chen ZC, Yuan C, Huang QG. Pulsar Timing Array Constraints on Primordial Black Holes with NANOGrav 11-Year Dataset. PHYSICAL REVIEW LETTERS 2020; 124:251101. [PMID: 32639789 DOI: 10.1103/physrevlett.124.251101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
The detection of binary black hole coalescences by LIGO and Virgo has aroused the interest in primordial black holes (PBHs), because they could be both the progenitors of these black holes and a compelling candidate of dark matter (DM). PBHs are formed soon after the enhanced scalar perturbations reenter horizon during the radiation dominated era, which would inevitably induce gravitational waves as well. Searching for such scalar induced gravitational waves (SIGWs) provides an elegant way to probe PBHs. We perform the first direct search for the signals of SIGWs accompanying the formation of PBHs in the North American Nanohertz Observatory for Gravitational waves (NANOGrav) 11-year dataset. No statistically significant detection has been made, and hence we place a stringent upper limit on the abundance of PBHs at 95% confidence level. In particular, less than one part in a million of the total DM mass could come from PBHs in the mass range of [2×10^{-3},7×10^{-1}] M_{⊙}.
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Affiliation(s)
- Zu-Cheng Chen
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, United Kingdom
| | - Chen Yuan
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
| | - Qing-Guo Huang
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
- Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009, China
- Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha 410081, China
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Liu J, Guo ZK, Cai RG. Analytical approximation of the scalar spectrum in the ultraslow-roll inflationary models. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.101.083535] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tomikawa K, Kobayashi T. Gauge dependence of gravitational waves generated at second order from scalar perturbations. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.101.083529] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Hajkarim F, Schaffner-Bielich J. Thermal history of the early Universe and primordial gravitational waves from induced scalar perturbations. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.101.043522] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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