Related papers: Double-Diffusive Mixing-Length Theory, Semiconvect…
The results of recent multi-dimensional simulations of type-II supernovae are reviewed. They show that convective instabilities in the collapsed stellar core might play an important role already during the first second after the formation…
We study the linear evolution of small perturbations in self-gravitating fluid systems in two spatial dimensions; we consider both cylindrical and cartesian (i.e., slab) geometries. The treatment is general, but the application is to…
In this note, we investigate a doubly nonlinear diffusion equation in the slow diffusion regime. We prove stability of the pressure of solutions that are close to traveling wave solutions in a homogeneous Lipschitz sense. We derive…
Since 1995, more than 500 extrasolar planets have been discovered orbiting very close to their parent star, where they experience strong tidal interactions. Their orbital evolution depends on the physical mechanisms that cause tidal…
The study of shear layer instability in compressible flows is key to understanding phenomena from aerodynamics to astrophysical jets. Blumen's seminal paper [``Shear layer instability of an inviscid compressible fluid," J. Fluid Mech. {\bf…
Convection in astrophysical systems must be maintained against dissipation. Although the effects of dissipation are often assumed to be negligible, theory suggests that in strongly stratified convecting fluids, the dissipative heating rate…
We couple two-dimensional hydrodynamics to detailed one-dimensional multigroup flux-limited diffusion neutrino transport to investigate prompt convection in core collapse supernovae. Our initial conditions, time-dependent boundary…
It is debated whether close-in giant planets can form in-situ and if not, which mechanisms are responsible for their migration. One of the observable tests for migration theories is the current value of the angle between the stellar…
We study the dynamical stability and fates of hierarchical (in semi-major axis) two-planet systems with arbitrary eccentricities and mutual inclinations. We run a large number of long-term numerical integrations and use the Support Vector…
A one-dimensional turbulent convection model in the form of a time-dependent diffusion equation for the turbulent energy is incorporated into our numerical pulsation code. The effect of turbulent convection on the structural rearrangement…
The isothermal spatio-temporal evolution of an interface between binary fluids, with temperature sensitive miscibility gap, subjected to shear flow is investigated using direct numerical simulations. The thermophysical properties and the…
Direct numerical simulations are conducted for double diffusive convection (DDC) bounded by two parallel plates, with fluid properties similar to the values of seawater. The DDC flow is driven by an unstable salinity difference and…
We present a rigorous proof establishing the mathematical equivalence between two independent criteria for the marginal stability of multi-fluid relativistic stars: the dynamical criterion based on the vanishing of the fundamental radial…
In this paper we investigate the convection phenomenon in the intracluster medium (the weakly-collisional magnetized inhomogeneous plasma permeating galaxy clusters) where the concentration gradient of the Helium ions is not ignorable. To…
Both observations and numerical simulations show that stellar convective motions are composed of semi-regular flows of convective rolling cells and the fully developed turbulence. Although the convective rolling cells are crucial for the…
The turbulent burning of nuclei is a common phenomenon in the evolution of stars. Here we examine a challenging case: the merging of the neon and oxygen burning shells in a 23 M$_{\odot}$ star. A previously unknown quasi-steady state is…
Stellar evolution models calculate convective boundaries using either the Schwarzschild or Ledoux criterion, but confusion remains regarding which criterion to use. Here we present a 3D hydrodynamical simulation of a convection zone and…
Convective instability in a ferrofluid layer heated from below or from above in the presence of a uniform vertical magnetic field is investigated theoretically. Convection is caused by a magnetic mechanism based on the temperature and…
Highly condensed gaseous objects with masses larger than 5x10^4 M_sun are called super-massive stars. In the quasistationary contraction phase, the hydrostatic equilibrium is determined by radiation pressure and gravitation. The global…
We have derived a new expression for the thermohaline mixing coefficient in stars, including the effects of radiative levitation and external turbulence, by solving Boussinesq equations in a quasi-incompressible fluid with a linear…