Related papers: Disks as Inhomogeneous, Anisotropic Gaussian Rando…
We investigate the stability to nonaxisymmetric perturbations of an accretion disc in which a poloidal magnetic field provides part of the radial support against gravity. Interchange instability due to radial gradients in the magnetic field…
In this paper we explore the connection between anisotropic Gaussian fluctuations and isotropic non-Gaussian fluctuations. We first set up a large angle framework for characterizing non-Gaussian fluctuations: large angle non-Gaussian…
Coherent oscillations associated with spin precessions were observed in ultrafast optical experiments on ferromagnetic (Ga,Mn)As films. Using a complete theoretical description of the processes by which light couples to the magnetization,…
In the interstellar medium of galaxies and the intracluster gas of galaxy clusters, the charged particles making up cosmic rays are moving almost exclusively along (but not across) magnetic field lines. The resulting anisotropic transport…
Rapidly growing black holes are surrounded by accretion disks that make them the brightest objects in the Universe. Their brightness is known to be variable, but the causes of this are not implied by simple disk models and still debated.…
A model of a galactic disk is presented which extends the homogeneous one zone models by incorporating propagation of material and energy in the disk. For reasonable values of the parameters the homogeneous steady state is unstable to the…
We discuss the construction of cosmological models within the framework of Macroscopic Gravity (MG), which is a theory that models the effects of averaging the geometry of space-time on large scales. We find new exact spatially homogeneous…
External matter distributions can substantially reshape the strong field environment of compact objects, yet this effect is usually neglected in idealized isolated models. In this work, we investigate geometrically thin, optically thick…
Ultralight axion-like particles are well-motivated dark matter candidates that are the target of numerous direct detection efforts. In the vicinity of the Solar System, such particles can be treated as oscillating scalar fields. The…
Accretion occurs across a large range of scales and physical regimes. Despite this diversity in the physics, the observed properties show remarkably similarity. The theory of propagating fluctuations, in which broad-band variability within…
We study the local times of a large class of Gaussian random fields satisfying strong local nondeterminism with respect to an anisotropic metric. We establish moment estimates and H\"{o}lder conditions for the local times of the Gaussian…
Previous models have shown that stochastic scattering of stars in a two-dimensional galaxy disc can generate a time-independent surface density distribution that is an exponential divided by radius when a constant inward scattering bias is…
An attempt is made to set constraints on the otherwise ambiguous decomposition of the rotation curves of low surface brightness galaxies into contributions due to the various components of the galaxies. For this purpose galaxies are…
The model of an young star with a protoplanetary disk and a low-mass companion, which is moving on a circular orbit, inclined to the disk plane, is considered. The hydrodynamic models of such a system were calculated by SPH method. It was…
The redshift of light is calculated for an anisotropic cosmological spacetime. Two different approaches are considered. In the first one, electromagnetic waves are modeled using the geometrical optics (high--frequency) approximation. This…
The growth of magneto-hydrodynamic fluctuations relevant to cosmic ray confinement in and near their sources, and the effects of local plasma conditions is revisited. We consider cases where cosmic rays penetrate a medium which may contain…
The drift and diffusion coefficients of the inhomogeneous multi-mass degenerate Landau equation are computed to describe the self-induced resonant relaxation of a discrete self-gravitating quasi-Keplerian razor-thin axisymmetric disc…
We present a scenario for the formation of disks which explains not only the properties of normal galaxies, but the properties of the population of low surface brightness galaxies (LSBs) as well. We use a gravitationally self-consistent…
Recent work on the mass distribution in spiral galaxies, using mainly HI observations, is reviewed. The principal problem is still to determine to what extent the dark matter is important in the inner parts of a galaxy, or in other words,…
The macroscopic behaviour of cosmic rays in turbulent magnetic fields is discussed. An implementation of anisotropic diffusion of cosmic rays with respect to the magnetic field in a non-conservative, high-order, finite-difference…