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Related papers: Bulk viscosity in hyperonic star and r-mode instab…

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Motivated by the existence of unstable modes of compact stars that eventually grow large, we study the bulk viscosity of dense matter, taking into account non-linear effects arising in the large amplitude regime, where the deviation…

Nuclear Theory · Physics 2011-02-01 Mark G. Alford , Simin Mahmoodifar , Kai Schwenzer

In this work, we have calculated the transport coefficients: shear viscosity and thermal conductivity inside the neutron star core. Our calculation is based on the relativistic kinetic theory approach using a modified BUU equation for…

Nuclear Theory · Physics 2026-03-20 Utsab Gangopadhyaya , Suman Pal , Gargi Chaudhuri

We develop a new perturbative framework for studying the r-modes of rotating superfluid neutron stars. Our analysis accounts for the centrifugal deformation of the star, and considers the two-fluid dynamics at linear order in the perturbed…

Solar and Stellar Astrophysics · Physics 2015-05-13 B. Haskell , N. Andersson , A. Passamonti

A general formalism for calculating the bulk viscosity of strange quark matter is developed. Contrary to the common belief that the non-leptonic processes alone give the dominant contribution to the bulk viscosity, the inclusion of the Urca…

Astrophysics · Physics 2008-11-26 Basil A. Sa'd , Igor A. Shovkovy , Dirk H. Rischke

Diffferentially rotating stars can support significantly more mass in equilibrium than nonrotating or uniformly rotating stars, according to general relativity. The remnant of a binary neutron star merger may give rise to such a…

Astrophysics · Physics 2009-10-31 Stuart L. Shapiro

We analyze the viscous damping of r-mode oscillations of compact stars, taking into account non-linear viscous effects in the large-amplitude regime. The qualitatively different cases of hadronic stars, strange quark stars, and hybrid stars…

High Energy Astrophysical Phenomena · Physics 2013-05-30 Mark G. Alford , Simin Mahmoodifar , Kai Schwenzer

Recently Andersson et. al., and Bildsten have independently suggested that an r-mode instability might be responsible for stalling the neutron-star spin-up in strongly accreting, Low Mass X-ray Binaries (LMXBs). We show that if this does…

Astrophysics · Physics 2009-10-31 Yuri Levin

We calculate the spectrum of inertial oscillation modes in a slowly rotating superfluid neutron star, including, for the first time, both the effects of finite temperatures and entrainment between superfluid neutrons and protons. We work in…

High Energy Astrophysical Phenomena · Physics 2018-11-07 Vasiliy A. Dommes , Elena M. Kantor , Mikhail E. Gusakov

Viscosity plays a critical role in determining the stability of rotating neutron stars. We report the results of a calculation of the shear viscosity of $\beta$~-~stable matter, carried out using an effective interaction based on a…

Nuclear Theory · Physics 2009-12-02 Omar Benhar , Arianna Carbone

The gravitational-wave and accretion driven evolution of the angular velocity, core temperature, and (small) amplitude of an r-mode of neutron stars in low mass X-ray binaries and similar systems is investigated. The conditions required for…

Astrophysics · Physics 2009-11-07 Robert V. Wagoner

We describe how the nonlinear development of the R mode instability of neutron stars influences spin up to millisecond periods via accretion. Our arguments are based on nearly-resonant interactions of the R mode with pairs of "daughter…

Solar and Stellar Astrophysics · Physics 2013-10-30 Ruxandra Bondarescu , Ira Wasserman

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

The properties of neutron stars are studied in a composite model of the strong interaction. In the regime of low to medium baryonic densities a covariant hadronic model is adopted which includes an exclusive channel for the hyperon-hyperon…

Nuclear Theory · Physics 2023-12-21 R. M. Aguirre

For the analysis of the r-mode oscillation of hot young neutron stars, it is necessary to consider the effect of it differential rotation, because viscosity is not strong enough for differentially rotating young neutron stars to be lead to…

Astrophysics · Physics 2009-10-31 S. Karino , S. Yoshida , Y. Eriguchi

We proposed alternative explanation to the rapid cooling of neutron star in Cas A. It is suggested that the star is experiencing the recovery period following the r-mode heating process,assuming the star is differentially rotating. Like the…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Shu-Hua Yang , Chun-Mei Pi , Xiao-Ping Zheng

A brief review of the stability of rotating relativistic stars is followed by a more detailed discussion of recent work on an instability of r-modes, modes of rotating stars that have axial parity in the slow-rotation limit. These modes may…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John L. Friedman , Keith H. Lockitch

We present new results on dynamical instabilities in rapidly rotating neutron-stars. In particular, using numerical simulations in full General Relativity, we analyse the effects that the stellar compactness has on the threshold for the…

Astrophysics · Physics 2008-11-26 G. M. Manca , L. Baiotti , R. De Pietri , L. Rezzolla

We discuss the effects induced by the potential presence of hyperons in hot and ultra-dense matter within the context of neutron star mergers. Specifically, we address their effect on the dominant post-merger frequency of the gravitational…

High Energy Physics - Phenomenology · Physics 2024-11-25 Hristijan Kochankovski , Angels Ramos , Laura Tolos , Sebastian Blacker , Andreas Bauswein

We present the first multi-fluid analysis of a dense neutron star core with a deconfined colour-flavour-locked superconducting quark component. Accounting only for the condensate and (finite temperature) phonons, we make progress by taking…

Solar and Stellar Astrophysics · Physics 2014-11-21 N. Andersson , B. Haskell , G. L. Comer

The loss of angular momentum due to unstable r-modes in hot young neutron stars has been proposed as a mechanism for achieving the spin rates inferred for young pulsars. One factor that could have a significant effect on the action of the…

Astrophysics · Physics 2009-11-07 Anna. L. Watts , Nils. Andersson