English
Related papers

Related papers: Bulk Viscosity in Dense Nuclear Matter

200 papers

We study out-of-thermodynamic equilibrium effects in neutron star mergers with 3D general-relativistic neutrino-radiation large-eddy simulations. During merger, the cores of the neutron stars remain cold ($T \sim$ a few MeV) and out of…

We generalize the problem of strongly interacting neutron matter by adding a periodic external modulation. This allows us to study from first principles a neutron system that is extended and inhomogeneous, with connections to the physics of…

Nuclear Theory · Physics 2016-04-13 Mateusz Buraczynski , Alexandros Gezerlis

Neutron stars provide a natural laboratory for studying the properties of dense nuclear matter under extreme conditions. In this proceeding, we review our current understanding of dense isospin symmetric and asymmetric matter and neutron…

Nuclear Theory · Physics 2025-04-01 Rajesh Kumar , Veronica Dexheimer , Johannes Jahan

Out-of-equilibrium reactions between different particle species are the main processes contributing to bulk viscosity in neutron stars. In this work, we numerically compare three different approaches to the modeling of bulk viscosity: the…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Giovanni Camelio , Lorenzo Gavassino , Marco Antonelli , Sebastiano Bernuzzi , Brynmor Haskell

The current picture of the collapse and explosion of massive stars and the formation of neutron stars is reviewed. According to the favored scenario, however by no means proven and undisputed, neutrinos deposit the energy of the explosion…

Astrophysics · Physics 2010-11-19 H. -Th. Janka , K. Kifonidis , M. Rampp

Formed in the aftermath of gravitational core-collapse supernova explosions, neutron stars are unique cosmic laboratories for probing the properties of matter under extreme conditions that cannot be reproduced in terrestrial laboratories.…

Nuclear Theory · Physics 2019-03-06 David Blaschke , Nicolas Chamel

Within a Boltzmann transport model, we demonstrate correlation between stopping observables and shear viscosity in central nuclear collisions at intermediate energies (on the order of 10 to 1000 MeV/nucleon). The correlation allows us to…

Nuclear Theory · Physics 2019-03-27 Brent Barker , Pawel Danielewicz

In this work, we perform the first systematic investigation of effects of the presence of dark matter on $r$-mode oscillations in neutron stars (NSs). Using a self-interacting dark matter (DM) model based on the neutron decay anomaly and a…

High Energy Astrophysical Phenomena · Physics 2023-12-15 Swarnim Shirke , Suprovo Ghosh , Debarati Chatterjee , Laura Sagunski , Jürgen Schaffner-Bielich

Pulsar spin frequencies and their time evolution are an important source of information on compact stars and their internal composition. Oscillations of the star can reduce the rotational energy via the emission of gravitational waves. In…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Mark Alford , Simin Mahmoodifar , Kai Schwenzer

Neutron stars contain neutron-rich matter with around 5% protons at nuclear saturation density. In this Letter, we consider equilibrium between bulk phases of matter based on asymmetric nuclear matter calculations using chiral effective…

Nuclear Theory · Physics 2024-06-11 J. Keller , K. Hebeler , C. J. Pethick , A. Schwenk

The calculation of transport properties of Fermi liquids, based on the formalism developed by Abrikosov and Khalatnikov, requires the knowledge of the probability of collisions between quasiparticles in the vicinity of the Fermi surface. We…

Nuclear Theory · Physics 2008-11-26 Omar Benhar , Marco Valli

The bulk viscosity of cold, dense three-flavor quark matter is studied as a function of temperature and the amplitude of density oscillations. The study is also extended to the case of two different types of anharmonic oscillations of…

Nuclear Theory · Physics 2015-03-17 Igor A. Shovkovy , Xinyang Wang

We propose a new model for the viscosity of cosmic matters, which can be applied to different epochs of the universe. Using this model, we include the bulk viscosities as practical corrections to the perfect fluid models of the baryonic and…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Jing Yang , Rui-Hui Lin , Xiang-Hua Zhai

Burst oscillations, a phenomenon observed in a significant fraction of Type I (thermonuclear) X-ray bursts, involve the development of highly asymmetric brightness patches in the burning surface layers of accreting neutron stars.…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Anna L. Watts

Gravitational and hydrodynamical perturbations are analysed in a relativistic plasma containing a mixture of interacting fluids characterized by a non-negligible bulk viscosity coefficient. The energy-momentum transfer between the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Massimo Giovannini

We conduct a systematic investigation of the influence of the nuclear symmetry energy on the proposed neutron decay into dark matter particles within the cores of neutron stars. Unlike the majority of previous studies that considered only…

Nuclear Theory · Physics 2025-09-01 M. Divaris , Ch. C. Moustakidis

Recent equations of state for dense nuclear matter are discussed with possible phase transitions arising in neutron stars such as pion, kaon and hyperon kondensation, superfluidity and quark matter. Specifically, we treat the nuclear to…

Nuclear Theory · Physics 2009-10-31 H. Heiselberg , M. Hjorth-Jensen

Binary neutron star mergers provide a unique laboratory for studying matter under conditions that cannot be reproduced in terrestrial experiments. They probe dense matter at supranuclear density, finite temperature, rapid rotation, strong…

High Energy Astrophysical Phenomena · Physics 2026-05-27 Armen Sedrakian

We discuss the possibility to implement a viscous cosmological model, attributing to the dark matter component a behaviour described by bulk viscosity. Since bulk viscosity implies negative pressure, this rises the possibility to unify the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-04 C. M. S. Barbosa , J. C. Fabris , O. F. Piattella , H. E. S. Velten , W. Zimdahl

The stability of the $\beta$-equilibrated dense nuclear matter is analyzed with respect to the thermodynamic stability conditions. Based on the density dependent M3Y effective nucleon-nucleon interaction, the effects of the nuclear…

Nuclear Theory · Physics 2014-09-05 Debasis Atta , D. N. Basu