We have investigated the influence of jet rotation and differential motion on the linear and nonlinear development of the current-driven (CD) kink instability of force-free helical magnetic equilibria via threedimensional relativistic magnetohydrodynamic simulations. In this study, we follow the temporal development within a periodic computational box. Displacement of the initial helical magnet...

Aims. To establish the dominant wave modes generated by an internal, m = 1 kink instability in a short coronal flux tube. Methods. The 3D MHD numerical simulations are performed using Lare3d to model the kink instability and the subsequent wave generation. The initial conditions are a straight, zero net current flux tube containing a twist higher than the kink instability threshold. Results. It...

We have investigated the development of current-driven (CD) kink instability through three-dimensional relativistic MHD simulations. A static force-free equilibrium helical magnetic configuration is considered in order to study the influence of the initial configuration on the linear and nonlinear evolution of the instability. We found that the initial configuration is strongly distorted but no...

Aims. Previous work on the dynamics of the kink instability has concentrated on the evolution of the magnetic field and associated current sheets. Here we aim to determine the observational consequences of the kink instability in short coronal loops, particularly what images TRACE would record of such an instability. This paper concentrates on the internal m = 1 mode where the kink structure of...

We study the equilibria of a self-gravitating scalar field in the region outside a reflecting barrier. By introducing a potential difference between the barrier and infinity, we create a kink which cannot decay to a zero-energy state. In the realm of a small amplitude, the kink decays to a known static solution of the Einstein-Klein-Gordon equation. However, for larger kinks the static equilibr...

We study the current-driven kink instability with a three-dimensional MHD spectral code, under conditions appropriate for the convection zone of the Sun. Our goal is to determine whether the kink instability can explain the unusual morphology of certain ““ d-spot ÏÏ active regions. The characteristics of these d-spots are unusually large tilt upon emergence, subsequent rotation, compactness dur...

We perform three-dimensional simulations of the rise of twisted magnetic Ñux tubes in an adiabatically stratiÐed model solar convection zone. The initial Ñux tube in our simulations is a uniformly twisted, buoyant, horizontal tube located near the bottom of the stratiÐed layer. The twist of the initial Ñux tube is described by a parameter a, which is deÐned as the angular rate of Ðeld-line rota...

Current-driven instabilities of force-free screw pinches are studied for a large variety of magnetic configurations by means of a global linear analysis in an ideal MHD framework. The magnetic pitch, P = rBz/Bφ, in particular its value on the axis, P0, essentially determines the growth rate of the fastest growing kink instability and allows to identify two regimes. In the large pitch regime, re...