Related papers: Global drag-induced instabilities in protoplanetar…
We use the Fokker-Planck equation and its moment equations to study the collective behavior of interacting particles in unsteady one-dimensional flows. Particles interact according to a long-range attractive and a short-range repulsive…
We develop simple, physically motivated models for drag-induced dust-gas streaming instabilities, which are thought to be crucial for clumping grains to form planetesimals in protoplanetary disks. The models explain, based on the physics of…
Context. The model of disc fragmentation due to gravitational instabilities offers an alternate formation mechanism for gas giant planets, especially those on wide orbits. Aims. Our goal is to determine the 3D structure of disc-instability…
We identify and study a number of new, rapidly growing instabilities of dust grains in protoplanetary disks, which may be important for planetesimal formation. The study is based on the recognition that dust-gas mixtures are generically…
We perform numerical simulations of solid particle motion in a shearing box model of a protoplanetary disc. The accretion flow is turbulent due to the action of the magnetorotational instability. Aerodynamic drag on the particles is…
The dynamics of solid bodies in protoplanetary disks are subject to the properties of any underlying gas turbulence. Turbulence driven by disk self-gravity shows features distinct from those driven by the magnetorotational instability…
This paper considers gravitational perturbations in geometrically thin disks with rotation curves dominated by a central object, but with substantial contributions from magnetic pressure and tension. The treatment is general, but the…
Various instabilities have been proposed as a promising mechanism to accumulate dust. Moreover, some of them are expected to lead to the multiple-ring structure formation and the planetesimal formation in protoplanetary disks. In a…
This review introduces physical processes in protoplanetary disks relevant to accretion and the initial stages of planet formation. After a brief overview of the observational context, I introduce the elementary theory of disk structure and…
We discuss the stability of galactic disks in which the energy of interstellar clouds is gained in encounters with expanding supernova remnants and lost in inelastic collisions. Energy gain and loss processes introduce a phase difference…
Young protostellar discs are likely to be both self-gravitating, and to support grain growth to sizes where the particles decoupled from the gas. This combination could lead to short-wavelength fragmentation of the solid component in…
Both core accretion and disk instability appear to be required as formation mechanisms in order to explain the entire range of giant planets found in extrasolar planetary systems. Disk instability is based on the formation of clumps in a…
Planetary systems form in gas-dust protoplanetary discs via the growth of solid bodies. In this paper, we show that the most intriguing stage of such growth --- namely, the transformation of 1-10 m boulders into kilometre-sized…
We develop a simple model for computing planetary formation based on the core instability model for the gas accretion and the oligarchic growth regime for the accretion of the solid core. In this model several planets can form…
Protoplanetary discs may become dynamically unstable due to structure induced by an embedded giant planet. In this thesis, I discuss the stability of such systems and explore the consequence of instability on planetary migration. I begin…
We calculate the global quasi-steady state of a thin disk perturbed by a low-mass protoplanet orbiting at a fixed radius using extremely high-resolution numerical integrations of Euler's equations in two dimensions. The calculations are…
We study the migration of solid bodies in turbulent protoplanetary accretion discs by means of global MHD simulations. The bodies range in size from 5 centimetres up to 1 metre, and so include objects whose migration is expected to be the…
We present the latest development of the disk gravitational instability and fragmentation model, originally introduced by us to explain episodic accretion bursts in the early stages of star formation. Using our numerical hydrodynamics model…
We review the models and results of simulations of self-gravitating, gaseous protoplanetary disks in binary star systems. These models have been calculated by three different groups with three different computational methods, two…
We investigate where in protoplanetary disks magnetorotational instability operates, which can cause angular momentum transport in the disks. We investigate the spatial distribution of various charged particles and the unstable regions for…