25 citations · 35 across the 6 of their papers we have counts for
6 papers
Universal behaviour of -viscosity in black hole accretion discs
Marek A. Abramowicz, Axel Brandenburg, Jiří Horák +4
The Shakura-Sunyaev -viscosity coefficient, defined as the ratio of total stress to total pressure, , began to play an important role in the development of accr…
Stability of Rotating, Charged Fluids: Generalization of the Hoiland Conditions in Newtonian Non-conductive Case
Kris Schroven, Vladimir Karas, Jiri Horak +2
We study the conditions for stability of electrically charged, non-conductive perfect fluid tori with respect to linear perturbations. To this end we employ Lagrangian perturbation…
On the geometry of the -Laplacian operator
Bernd Kawohl, Jiri Horák
The -Laplacian operator is not uniformly elliptic for any and degenerates even more when $p\to \…
Polarization from the oscillating magnetized accretion torus
Jiri Horak, Michal Bursa
We study oscillations of accretion torus with azimuthal magnetic field. For several lowest-order modes we calculate eigenfrequencies and eigenfunctions and calculate corresponding…
Polarization of light from warm clouds above an accretion disk: effects of strong-gravity near a black hole
J. Horak, V. Karas
We study polarization from scattering of light on a cloud in radial motion along the symmetry axis of an accretion disk. Radiation drag from the disk and gravitational attraction o…
Of NBOs and kHz QPOs: a low-frequency modulation in resonant oscillations of relativistic accretion disks
J. Horak, M. Abramowicz, V. Karas +1
The origin of quasi periodic modulations of flux in the kilohertz range (kHz QPOs), observed in low-mass X-ray binaries, is usually assumed to be physically distinct from that of t…