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Related papers: Bulk viscosity in neutron stars with hyperon cores

200 papers

We calculated bulk viscosity due to non-equilibrium weak processes in superfluid nucleon-hyperon matter of neutron stars. For that, the dissipative relativistic hydrodynamics, formulated in paper [1] for superfluid mixtures, was extended to…

Astrophysics · Physics 2008-11-26 M. E. Gusakov , E. M. Kantor

In this work we study the r-mode instability windows and the gravitational wave signatures of neutron stars in the slow rotation approximation using the equation of state obtained from the density dependent M3Y effective interaction. We…

Nuclear Theory · Physics 2018-06-20 Somnath Mukhopadhyay , Joydev Lahiri , Debasis Atta , Kouser Imam , D. N. Basu

The detectability of the gravitational-wave signal from $r$-modes depends on the interplay between the amplification of the mode by the CFS instability and its damping due to dissipative mechanisms present in the stellar matter. The…

High Energy Astrophysical Phenomena · Physics 2025-08-06 Kirill Y. Kraav , Mikhail E. Gusakov , Elena M. Kantor

We present an analytic description of the $r$-mode instability in newly-born neutron stars, using the approximation of uniform density. Our computation is consistently accurate to second order in the angular velocity of the star. We obtain…

Astrophysics · Physics 2011-05-23 K. D. Kokkotas , N. Stergioulas

The bulk viscosity of the neutron star matter due to the direct Urca processes involving nucleons, electrons and muons is studied taking into account possible superfluidity of nucleons in the neutron star cores. The cases of singlet-state…

Astrophysics · Physics 2009-05-13 P. Haensel , K. P. Levenfish , D. G. Yakovlev

The early post-merger phase of a binary neutron-star coalescence is shaped by characteristic rotational velocities as well as violent density oscillations and offers the possibility to constrain the properties of neutron star matter by…

General Relativity and Quantum Cosmology · Physics 2025-03-10 Michail Chabanov , Luciano Rezzolla

The contribution from hyperons to the bulk viscosity of neutron star matter is calculated. Compared to previous works we use for the weak interaction the one-pion exchange model rather than a current-current interaction, and include the…

Nuclear Theory · Physics 2009-11-10 E. N. E. van Dalen , A. E. L. Dieperink

The gravitational radiation has been proposed a long time before, as an explanation for the observed relatively low spin frequencies of young neutron stars and of accreting neutron stars in low-mass X-ray binaries as well. In the present…

Solar and Stellar Astrophysics · Physics 2017-05-10 M. C. Papazoglou , C. C. Moustakidis

The GW190814 event, involving a black hole of mass $22.2$--$24.3 M_{\odot}$ and a compact object of mass $2.50$--$2.67 M_{\odot}$, challenges our understanding of the mass gap between the heaviest neutron stars and the lightest black holes.…

High Energy Astrophysical Phenomena · Physics 2026-03-09 Athira S , Monika Sinha

We study the viscous damping of r-modes of compact stars and analyze in detail the regions where small amplitude modes are unstable to the emission of gravitational radiation. We present general expressions for the viscous damping times for…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Mark Alford , Simin Mahmoodifar , Kai Schwenzer

Recent work has raised the exciting possibility that r-modes (Rossby waves) in rotating neutron star cores might be strong gravitational wave sources. We estimate the effect of a solid crust on their viscous damping rate and show that the…

Astrophysics · Physics 2009-10-31 Lars Bildsten , Greg Ushomirsky

We study the bulk viscosity in neutron star cores due to modified Urca processes involving nucleons, electrons and muons and analize its reduction by singlet-state or triplet-state superfluidity of nucleons. In combination with the results…

Astrophysics · Physics 2009-11-06 P. Haensel , K. P. Levenfish , D. G. Yakovlev

We calculate the finite-temperature r-mode spectrum of a slowly rotating superfluid Newtonian neutron star neglecting the entrainment between neutron and proton liquid components (i.e., neglecting the off-diagonal element of the entrainment…

High Energy Astrophysical Phenomena · Physics 2018-08-13 Elena M. Kantor , Mikhail E. Gusakov

As the densities in the interior of neutron stars exceed those of terrestrial nuclear experiments, they provide a scope for studying the nature of dense matter under extreme conditions. The composition of the inner core of neutron stars is…

High Energy Astrophysical Phenomena · Physics 2021-04-07 Bikram Keshari Pradhan , Debarati Chatterjee

Using a simple model of a neutron star with a perfectly rigid crust constructed and a set of crust and core equations of state that span the range of nuclear experimental uncertainty in the density dependence of the symmetry energy from 25…

Solar and Stellar Astrophysics · Physics 2015-05-30 De-Hua Wen , W. G. Newton , Bao-An Li

We perform a systematic study of the dependence of the r-mode phenomenology in normal fluid pulsar neutron stars on the symmetry energy slope parameter $L$. An essential ingredient in this study is the bulk viscosity, which is evaluated…

Nuclear Theory · Physics 2020-06-30 T. R. Routray , S. P. Pattnaik , C. Gonzalez-Boquera , X. Viñas , M. Centelles , B. Behera

A common alternative to the standard assumption of nucleonic composition of matter in the interior of a neutron star is to include strange baryons, particularly hyperons. Any change in composition of the neutron star core has an effect on…

Nuclear Theory · Physics 2023-07-26 Vinh Tran , Suprovo Ghosh , Nicholas Lozano , Debarati Chatterjee , Prashanth Jaikumar

We calculate the three bulk viscosity coefficients as arising from the collisions among phonons in superfluid neutron stars. We use effective field theory techniques to extract the allowed phonon collisional processes, written as a function…

High Energy Astrophysical Phenomena · Physics 2013-07-03 Cristina Manuel , Jaume Tarrus , Laura Tolos

In the present work, we explore the Rossby mode instabilities in neutron stars as sources of gravitational waves. The intensity and time evolution of the emitted gravitational waves in terms of the amplitude of the strain tensor are…

We study the bulk viscosity in two (anti-spaghetti and Swiss cheese) phases of non- spherical nuclei in the mantle of an oscillating neutron star near the boundary with the stellar core. The bulk viscosity is produced by non-equilibrium…

High Energy Astrophysical Phenomena · Physics 2018-10-17 D. G. Yakovlev , M. E. Gusakov , P. Haensel