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Related papers: Causal Viscosity in Accretion Disc Boundary Layers

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Black holes (BHs) surrounded by accretion disks are present in the Universe at different scales of masses, from microquasars up to the active galactic nuclei (AGNs). The current picture remains ad hoc due to the complexity of the magnetic…

High Energy Astrophysical Phenomena · Physics 2017-07-19 Mikołaj Grzędzielski , Agnieszka Janiuk , Bożena Czerny , Qingwen Wu

It was argued by Brigante et.al that the lower bound on the ratio of the shear viscosity to the entropy density in strongly coupled plasma is translated into microcausality violation in the dual gravitational description. Since transport…

High Energy Physics - Theory · Physics 2014-11-21 Alex Buchel , Sera Cremonini

Strong interaction among charge carriers can make them move like viscous fluid. Here we explore alternating current (AC) effects in viscous electronics. In the Ohmic case, incompressible current distribution in a sample adjusts fast to a…

Mesoscale and Nanoscale Physics · Physics 2018-02-21 Mykola Semenyakin , Gregory Falkovich

The equations governing the vertical structure of a stationary keplerian accretion disc are presented. The model is based on the alpha-viscosity, includes self-gravity, convective transport and turbulent pressure. A few properties of the…

Astrophysics · Physics 2016-08-30 Jean-Marc Hure

Hydrodynamic simulations have been used to study accretion disks consisting of counterrotating components with an intervening shear layer(s). Configurations of this type can arise from the accretion of newly supplied counterrotating matter…

Astrophysics · Physics 2009-10-31 O. A. Kuznetsov , R. V. E. Lovelace , M. M. Romanova , V. M. Chechetkin

Accretion disk theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was emitted to the sides of the disk. One of the most important new invention of this theory was the…

Astrophysics · Physics 2009-11-07 G. S. Bisnovatyi-Kogan , R. V. E. Lovelace

We consider the inner regions of accretion disks surrounding black holes and neutron stars and investigate the nonlinear time dependent evolution of thermal-viscous instabilities. The viscous stress is assumed to be proportional to the gas…

Astrophysics · Physics 2009-10-22 Xingming Chen , Ronald E. Taam

Variation of mass supply rate from the companion can be smeared out by viscous processes inside an accretion disk. By the time the flow reaches the inner edge, the variation in X-rays needs not reflect the true variation of the rate at the…

High Energy Astrophysical Phenomena · Physics 2019-04-08 Arindam Ghosh , Sandip Kumar Chakrabarti

In this paper, we establish vanishing viscosity limit of the 2D Navier-Stokes equations in a horizontally periodic strip. On the vertical direction, the horizontal component of the velocity is subjected to two different types of boundary…

Analysis of PDEs · Mathematics 2024-04-30 Mingwen Fei , Xinghong Pan , Jianfeng Zhao

In a reaction-diffusion-advection system, with a convectively unstable regime, a perturbation creates a wave train that is advected downstream and eventually leaves the system. We show that the convective instability coexists with a local…

Pattern Formation and Solitons · Physics 2017-10-11 Estefania Vidal-Henriquez , Vladimir Zykov , Eberhard Bodenschatz , Azam Gholami

This paper is concerned with nonlinear stability of viscous contact discontinuity to a free boundary problem for the one-dimensional full compressible Navier-Stokes equations in half space $[0,\infty)$. For the case when the local stability…

Analysis of PDEs · Mathematics 2014-10-09 Tingting Zheng

To produce a vortex, a torque must be applied to the fluid. In viscous fluids, the torques that produce turbulent vortices result from the loss of symmetry of the stress tensor, once the viscous friction exceeds the shear stress resistance…

General Physics · Physics 2020-04-21 A. Paglietti

Stellar oscillations are excited in non-synchronously rotating stars in binary systems due to the tidal forces. Tangential components of the tides can drive a shear flow which behaves as a differentially forced rotating structure in a…

We discuss the issues of stability of accretion disks that may undergo the limit-cycle oscillations due to the two main types of thermal-viscous instabilities. These are induced either by the domination of radiation pressure in the…

High Energy Astrophysical Phenomena · Physics 2013-01-01 Agnieszka Janiuk , Ranjeev Misra , Bozena Czerny , Magdalena Kunert-Bajraszewska

The diffusive viscous wave equation describes wave propagation in diffusive and viscous media. Examples include seismic waves traveling through the Earth's crust, taking into account of both the elastic properties of rocks and the…

Numerical Analysis · Mathematics 2025-01-13 Siyang Wang

The behaviour of a viscous drop squeezed between two horizontal planes is treated by both theory and experiment. When the squeezing force F is constant and surface tension is neglected, the theory predicts ultimate growth of the radius a~…

Fluid Dynamics · Physics 2021-03-29 Keith Moffatt , Howard Guest , Herbert Huppert

The viscous evolution of a thin disc around a central object is considered. Such discs are described by self-similar solutions in which either all or none of the inflowing mass accretes. An approximate solution for the partial accretion…

High Energy Astrophysical Phenomena · Physics 2012-10-22 K. Yavuz Ekşi

The interaction of a massive binary and a non-self-gravitating circumbinary accretion disc is considered. The shape of the stationary twisted disc produced by the binary is calculated. It is shown that the inner part of the disc must lie in…

Astrophysics · Physics 2009-10-31 P. B. Ivanov , J. C. B. Papaloizou , A. G. Polnarev

In this paper, the asymptotic-time behavior of solutions to an initial boundary value problem in the half space for 1-D isentropic Navier-Stokes system is investigated. It is shown that the viscous shock wave is stable for an impermeable…

Analysis of PDEs · Mathematics 2021-09-07 Lin Chang

The standard accretion discs are known to be thermally and viscously unstable over a certain range of temperatures. In the inner disc regions there may develop radiation pressure driven instability, which is possibly related to the rapid…

Astrophysics · Physics 2007-05-23 Agnieszka Janiuk , Bozena Czerny