Article
Astronomy & Astrophysics
Ankit Kumar, H. C. Das, S. K. Patra
Summary: Motivated by theoretical studies on efficient dark matter capture by neutron stars, this research explores the indirect effects of captured dark matter on the cooling mechanism of a neutron star. The study shows that varying dark matter momentum greatly modifies neutrino emissivity and investigates specific heat and thermal conductivity of a dark matter admixed star to explore cooling wave propagation within the star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Hristijan Kochankovski, Angels Ramos, Laura Tolos
Summary: The FSU2H equation-of-state model is extended to finite temperature and it is found that temperature has a stronger effect on thermodynamical observables and the composition of neutron star cores when considering hyperonic degrees of freedom. The widely used Gamma law is not appropriate to reproduce the true thermal effects, especially when hyperons become abundant in the neutron star core. Simple parametrizations of the thermal index for nucleonic and hyperonic beta-stable neutrino-free matter are provided to make finite temperature equations of state easily accessible.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
W. Z. Shangguan, Z. Q. Huang, S. N. Wei, W. Z. Jiang
Summary: The study shows that hyperons have a significant impact on the tidal deformability of neutron stars, and lower onset density of hyperons can considerably modify the deformability and affect the inference on the nuclear EOS.
Article
Astronomy & Astrophysics
Tsuyoshi Miyatsu, Myung-Ki Cheoun, Koichi Saito
Summary: Using the relativistic mean-field model, this study investigates the properties of isospin-asymmetric nuclear matter, considering the couplings between isoscalar and isovector mesons. The effects of vector mixing and quartic interactions on nuclear symmetry energy and neutron star properties are examined. The findings reveal that the delta meson increases nuclear symmetry energy at high densities, while the mixing of sigma and delta mesons softens the symmetry energy above the saturation density. The delta meson and its mixing also have a significant influence on the radius and tidal deformability of a neutron star. In particular, the mixing reduces the neutron star radius, allowing for a simultaneous reproduction of the observed tidal deformabilities of neutron stars.
ASTROPHYSICAL JOURNAL
(2022)
Article
Physics, Nuclear
Olfa Boukari, Helena Pais, Sofija Antic, Constanca Providencia
Summary: The study shows that although different equations of state are constrained by the same data, the properties of very asymmetric nuclear matter differ significantly among models. Some models predict larger transition densities to homogeneous matter for beta-equilibrated matter than for symmetric nuclear matter.
Article
Astronomy & Astrophysics
Billy K. K. Lee, Ming-chung Chu, Lap-Ming Lin
Summary: The investigation explores the possibility of a 2.6 M(circledot) compact object in the gravitational wave event GW190814 being a compact star admixed with bosonic dark matter. Constraints on the mass, radius, and stability of the object suggest that the dark matter may be composed of QCD axions, with their particle mass range potentially overlapping with constraints from black hole superradiance processes.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Multidisciplinary
Geraint Pratten, Patricia Schmidt, Natalie Williams
Summary: Gravitational waves provide a unique opportunity to infer the unknown equation of state of cold hadronic matter. Neglecting dynamical tidal effects can lead to large biases in the measured tidal deformability of neutron stars, affecting the accurate modeling of the equation of state. Accurately modeling subdominant tidal effects beyond the adiabatic limit is crucial for upcoming gravitational wave observations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
Peng-Cheng Chu, Yao-Yao Jiang, He Liu, Zhen Zhang, Xiao-Min Zhang, Xiao-Hua Li
Summary: The study shows that thermodynamic properties of asymmetric quark matter, large mass quark stars, and proto-quark stars are significantly influenced by temperature effects within the quasiparticle model. The recently discovered heavy compact stars can be well described as quark stars within the quasiparticle model.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Panagiotis Iosif, Nikolaos Stergioulas
Summary: The emergence of novel differential rotation laws has provided a way to construct equilibrium models that resemble the rotational profile of binary neutron star merger remnants in numerical simulations. The models have been successfully constructed using a 4-parameter differential rotation law and three tabulated equations of state. The results show that the chosen rotation law can accurately reproduce the threshold mass for prompt collapse to a black hole, with a relative difference of only about 1% compared to numerical simulations. Furthermore, the compactness of the equilibrium models at the threshold mass may be correlated with the compactness of maximum-mass non-rotating models. The study also finds a relatively slowly rotating inner region in the remnants, where the angular velocity is mostly due to frame dragging.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Particles & Fields
Peng-Cheng Chu, Yi Zhou, Yao-Yao Jiang, Hong-Yang Ma, He Liu, Xiao-Min Zhang, Xiao-Hua Li
Summary: The study suggests that a large symmetry energy of quark matter is required to describe the recently discovered heavy compact stars as QSs. Additionally, the investigation on tidal deformability Lambda(1.4) indicates its possible dependence on isospin effects and the distribution of magnetic fields inside quark stars.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Multidisciplinary Sciences
G. Fiorella Burgio, Hans-Josef Schulze, Isaac Vidana, Jin-Biao Wei
Summary: The study shows that almost all models are consistent with laboratory constraints and observations regarding nuclear matter properties, and no correlation was found between tidal deformability and the value of nuclear symmetry energy. However, very weak correlations might exist with the derivative of nuclear symmetry energy and nuclear incompressibility.
Article
Multidisciplinary Sciences
Plamen G. Krastev
Summary: Understanding the equation of state of dense neutron-rich matter is a major challenge in physics and astrophysics. Neutron star observations provide valuable insights into the behavior of dense neutron-rich matter. This work demonstrates the feasibility of using deep learning techniques to accurately determine the equation of state and related nuclear matter properties from neutron star observations.
Article
Multidisciplinary Sciences
Sabrina Huth, Peter T. H. Pang, Ingo Tews, Tim Dietrich, Arnaud Le Fevre, Achim Schwenk, Wolfgang Trautmann, Kshitij Agarwal, Mattia Bulla, Michael W. Coughlin, Chris Van den Broeck
Summary: Studying dense matter is crucial for understanding high-energy astrophysical phenomena, and data from heavy-ion collision experiments provide valuable insights in addition to astrophysical observations. By combining data from various sources, including heavy-ion collisions and microscopic nuclear theory calculations, researchers found significant improvements in their understanding of dense matter and its consistency with observations.
Article
Astronomy & Astrophysics
Zhenyu Zhu, Ang Li, Tong Liu
Summary: Observations of binary neutron star mergers provide insights into the abundance of heavy elements in the universe, the remnant object, and the properties of nuclear matter within the merging stars. A Bayesian inference approach is used to study the equation of state and properties of nuclear matter using the GW170817/AT2017gfo event and NICER mass-radius measurements. The results show a bimodal structure in the posterior distribution of reduced tidal deformability, indicating a softened equation of state enhanced by GW170817 data.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
J. Sedaghat, S. M. Zebarjad, G. H. Bordbar, B. Eslam Panah
Summary: We have performed a leading order perturbative calculation to obtain the equation of state (EoS) of strange quark matter (SQM) at zero temperature under a magnetic field B = 10(18) G. The obtained EoS is then used to calculate the maximum gravitational mass and corresponding radius of a magnetized strange quark star (SQS). The results show a maximum gravitational mass over three times the solar mass, and the validity of isotropic structure calculations for SQS is investigated.
Article
Physics, Multidisciplinary
Edward F. Brown, Andrew Cumming, Farrukh J. Fattoyev, C. J. Horowitz, Dany Page, Sanjay Reddy
PHYSICAL REVIEW LETTERS
(2018)
Article
Physics, Multidisciplinary
F. J. Fattoyev, J. Piekarewicz, C. J. Horowitz
PHYSICAL REVIEW LETTERS
(2018)
Article
Physics, Multidisciplinary
Jorge Piekarewicz, Farrukh J. Fattoyev
Article
Astronomy & Astrophysics
C. Y. Tsang, M. B. Tsang, Pawel Danielewicz, F. J. Fattoyev, W. G. Lynch
Article
Physics, Multidisciplinary
Brendan T. Reed, F. J. Fattoyev, C. J. Horowitz, J. Piekarewicz
Summary: Laboratory experiments sensitive to the equation of state of neutron rich matter in the vicinity of nuclear saturation density provide crucial data connecting terrestrial experiments to astronomical observations. The neutron skin thickness of Pb-208 further constrains the density dependence of the symmetry energy. The impact of a stiff symmetry energy on critical neutron-star observables is studied.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Melissa Mendes, Farrukh J. Fattoyev, Andrew Cumming, Charles Gale
Summary: Modeling of crust heating and cooling in MXB 1659-29, a low mass X-ray binary system, suggests that the neutrino luminosity of the neutron star core is consistent with dUrca reactions occurring in approximately 1% of the core volume. The neutron star mass is found to depend sensitively on the slope of the nuclear symmetry energy and the choice of superfluid gaps. The study explores different combinations of superfluid gaps to reproduce the inferred neutrino luminosity and discusses the possibility of alternative cooling processes in exotic neutron star cores. Future observations could provide further constraints on neutron star properties and the density dependence of the symmetry energy.
ASTROPHYSICAL JOURNAL
(2022)
Article
Physics, Nuclear
F. J. Fattoyev, C. J. Horowitz, J. Piekarewicz, Brendan Reed
Article
Physics, Nuclear
C. Y. Tsang, M. B. Tsang, Pawel Danielewicz, W. G. Lynch, F. J. Fattoyev
Article
Physics, Nuclear
C. Y. Tsang, B. A. Brown, F. J. Fattoyev, W. G. Lynch, M. B. Tsang
Article
Mathematics
Farrukh J. Fattoyev
ARABIAN JOURNAL OF MATHEMATICS
(2019)
Article
Physics, Nuclear
J. Piekarewicz, F. J. Fattoyev
Article
Physics, Nuclear
F. J. Fattoyev, Edward F. Brown, Andrew Cumming, Alex Deibel, C. J. Horowitz, Bao-An Li, Zidu Lin
Article
Physics, Nuclear
F. J. Fattoyev, C. J. Horowitz, B. Schuetrumpf
Article
Physics, Nuclear
Andrew Cumming, Edward F. Brown, Farrukh J. Fattoyev, C. J. Horowitz, Dany Page, Sanjay Reddy
Proceedings Paper
Astronomy & Astrophysics
Xiao-Tao He, F. J. Fattoyev, Bao-An Li, W. G. Newton
13TH INTERNATIONAL SYMPOSIUM ON ORIGIN OF MATTER AND EVOLUTION OF GALAXIES (OMEG2015)
(2016)
