Related papers: Faraday resonance in dynamical bar instability of …
We study the damping of the gravitational radiation-driven f-mode instability in rotating neutron stars by nonlinear bulk viscosity in the so-called supra-thermal regime. In this regime the dissipative action of bulk viscosity is known to…
We constrain the fundamental-mode ($f$-mode) oscillation frequencies of nonrotating neutron stars using a phenomenological Gaussian process model for the unknown dense-matter equation of state conditioned on a suite of gravitational-wave,…
We examine the dynamics of a particle in a general rotating quadratic potential, not necessarily stable or isotropic, using a general complex mode formalism. The problem is equivalent to that of a charged particle in a quadratic potential…
We find that nuclear rings in barred galaxies can be subject to a new type of non-self-gravitational dynamical instability. The instability leads to the formation of gaseous molecular bars with pattern speeds which are substantially slower…
It is shown that the monochromatic optical wave propagating through the medium with linear birefringence in presence of a signal electromagnetic wave (whose wavelength is equal to the polarization beats length), displays Faraday rotation…
Studies have shown that emission of gravitational wave drives an instability in the $r$-modes of young rapidly rotating neutron stars carrying away most of the angular momentum through gravitational wave emission in the first year or so…
$f(R)$ theories of gravity are one of the most popular alternative explanations for dark energy and therefore studying the possible astrophysical implications of these theories is an important task. In the present paper we make a…
Tayler instability of toroidal magnetic fields $B_\phi$ is broadly invoked as a trigger for turbulence and angular momentum transport in stars. This paper presents a systematic revision of the linear stability analysis for a rotating,…
We use perturbation theory and the relativistic Cowling approximation to numerically compute characteristic oscillation modes of rapidly rotating relativistic stars which consist of a perfect fluid obeying a polytropic equation of state. We…
We discovered an oscillatory instability in a system of inelastically colliding hard spheres, driven by two opposite "thermal" walls at zero gravity. The instability, predicted by a linear stability analysis of the equations of granular…
Targets for ground-based gravitational wave interferometers include continuous, quasiperiodic sources of gravitational radiation, such as isolated, spinning neutron stars. In this work we perform evolution simulations of uniformly rotating,…
In the present paper we examine gravitational wave asteroseismology relations for f-modes of rapidly rotating neutron stars. An approach different to the previous studies is employed - first, the moment of inertia is used instead of the…
The Rossby wave instability, associated with density bumps in differentially rotating discs, may arise in several different astrophysical contexts, such as galactic or protoplanetary discs. While the linear phase of the instability has been…
Rotational Fresnel drag - or orbital Faraday rotation - in a rotating magnetised plasma is uncovered and studied analytically for Trivelpiece-Gould and Whistler-Helicon waves carrying orbital angular momentum (OAM). Plasma rotation is shown…
Magnetohydrodynamic (MHD) instabilities can play an important role in the structure and dynamics of the pulsar magnetosphere. We consider the instabilitycaused by differential rotation that is suggested by many theoretical models. Stability…
Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because…
In general relativity, it has been shown that radiation-supported atmospheres exist outside the surface of a radiating spherical body close to a radius where the gravitational and radiative forces balance each other. We calculate the…
The linear stability of rapid granular flow on a slope under gravity against the longitudinal perturbation is analyzed using hydrodynamic equations. It is demonstrated that the steady flow uniform along the flow direction becomes unstable…
Material accreted onto a neutron star can stably burn in steady state only when the accretion rate is high (typically super-Eddington) or if a large flux from the neutron star crust permeates the outer atmosphere. For such situations we…
Using time evolutions of the relevant linearised equations we study non-axisymmetric oscillations of rapidly rotating and superfluid neutron stars. We consider perturbations of Newtonian axisymmetric background configurations and account…