2011/03/31 by Mark G. Alford, Mark Alford, Simin Mahmoodifar +1 · 2 citations
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Amplitude #Astrophysics #Classical mechanics #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #Instability #Magnetic damping #Mathematics #Mechanics #Mode (computer interface) #Physics #Pulsars and Gravitational Waves Research #Quantum electrodynamics #Quantum mechanics #Saturation (graph theory) #Stars #Viscosity #Viscous damping #astro-ph.HE #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.85.044051
18 pages, 17 figures, changed convention for the r-mode amplitude, version to be published in PRD
arxiv created 2012/02/09 · openalex publication_date 2012/02/22 · arxiv updated 2013/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We analyze the viscous damping of r-mode oscillations of compact stars, taking into account nonlinear viscous effects in the large-amplitude regime. The qualitatively different cases of hadronic stars, strange quark stars, and hybrid stars are studied. We calculate the viscous damping times of r-modes, obtaining numerical results and also general approximate analytic expressions that explicitly exhibit the dependence on the parameters that are relevant for a future spin-down evolution calculation. The strongly enhanced damping of large-amplitude oscillations leads to damping times that are considerably lower than those obtained when the amplitude dependence of the viscosity is neglected. Consequently, large-amplitude viscous damping competes with the gravitational instability at all physical frequencies and could stop the r-mode growth in case this is not done before by nonlinear hydrodynamic mechanisms.