Related papers: Star Stability and Star Regularity for Mori Domain…
We study the gravitational stability of gaseous streams in the complex environment of a galaxy merger, because mergers are known to be places of ongoing massive cluster formation and bursts of star formation. We find an analytic stability…
Polarized ferrofluids, lipid monolayers and magnetic bubbles form domains with deformable boundaries. Stability analysis of these domains depends on a family of nontrivial integrals. We present a closed form evaluation of these integrals as…
We present new results on instabilities in rapidly and differentially rotating neutron stars. We model the stars in full general relativity and describe the stellar matter adopting a cold realistic equation of state based on the unified SLy…
In 1977, Flowers and Ruderman described a perturbation that destabilises a purely dipolar magnetic field in a fluid star. They considered the effect of cutting the star in half along a plane containing the symmetry axis and rotating each…
We investigate the stability of the Hall-MHD system and determine its importance for neutron stars at their birth, when they still consist of differentially rotating plasma permeated by extremely strong magnetic fields. We solve the…
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,…
The configuration of the magnetic field in the interior of a neutron star is mostly unknown from observations. Theoretical models of the interior magnetic field geometry tend to be oversimplified to avoid mathematical complexity and tend to…
The study of the magnetic field in stellar radiation zones is an important topic in modern astrophysics because the magnetic field can play an important role in several transport phenomena such as mixing and angular momentum transport. We…
In this paper we propose a notion of stability, that we call $\epsilon -N$-stability, for systems of particles interacting via Newton's gravitational potential, and orbiting a much bigger object. For these systems the usual thermodynamical…
We implement a semi-analytic approach for stability analysis, addressing the ongoing uncertainty about stability and structure of neutron star magnetic fields. Applying the energy variational principle, a model system is displaced from its…
Parameter regions in which stars can become pulsationally unstable are found throughout the Hertzsprung-Russel diagram. Stars of high, intermediate, low and very low masses may cross various instability regions along their paths of…
We study the stability of neutron stars with toroidal magnetic fields by magnetohydrodynamic simulation in full general relativity under assumption of axial symmetry. Nonrotating and rigidly rotating neutron stars are prepared for a variety…
The electromagnetic field in a magnetized neutron star and the underlying volume charges and currents are found. A general case of a rigidly rotating neutron star with infinite conductivity, arbitrary distribution of the internal magnetic…
In this paper our aim is to determine the radii of univalence, starlikeness and convexity of the normalized regular Coulomb wave functions for two different kinds of normalization. The key tools in the proof of our main results are the…
Stars with a different vertical motion relative to the galactic disk have a different average acceleration. According to Modified Newtonian Dynamics (MOND) theories they should therefore have a different average orbital velocity while…
We study oscillations and instabilities of relativistic stars using perturbation theory in general relativity and take into account the contribution of a dynamic spacetime. We present the oscillation spectrum as well as the critical values…
Several recent surprises appear dramatically to have improved the likelihood that the spin of rapidly rotating, newly formed neutron stars (and, possibly, of old stars spun up by accretion) is limited by a nonaxisymmetric instability driven…
We study boson star configurations with generic, but not non-topological, self-interaction terms, i.e. we do not restrict ourselves just to consider the standard $\lambda |\psi|^4$ interaction but more general U(1)-symmetry-preserving…
Dynamical models of star clusters are maturing in the sense that effects other than simple point particle dynamics are taken into account. We summarize the relevance of and prospects for this new generation of N-body models.
We construct steady states of the Euler-Poisson system with a barotropic equation of state as minimizers of a suitably defined energy functional. Their minimizing property implies the non-linear stability of such states against general,…