An exact treatment of the stability of multilayered viscous fluids in slow motion with large deformations leads to an analog model which includes the effect of gravity. A distinction can be made between true mechanical instability and an apparent instability of purely kinematic nature. A mechanism for concentric folding is derived, leading to predictions in good agreement with experimental resu...

The D2-D0 bound state exhibits a Gregory-Laflamme instability when it is sufficiently non-extremal. If there are no D0-branes, the requisite non-extremality is finite. When most of the extremal mass comes from D0-branes, the requisite non-extremality is very small. The location of the threshold for the instability is determined using a local thermodynamic analysis which is then checked against ...

The stability problem of the rotation induced electrostatic wave in extragalactic jets is presented. Solving a set of equations describing dynamics of a relativistic plasma flow of AGN jets, the instability rate has been derived and estimated for typical values of extragalactic jets. The growth rate was analyzed versus the wave length and inclination angle and it has been found that the instabi...

In this work, we study the interaction between a tearing mode and a pressure gradient instability (resistive interchange) by solving reduced MHD equations numerically. The numerical study shows existence of regimes where thetearing instability is driven by the pressure gradient. An interplay between the pressure and the magnetic flux controls the dynamics of the saturated state. A secondary ins...

We prove some instability phenomena for semi-classical (linear or) nonlinear Schrödinger equations. For some perturbations of the data, we show that for very small times, we can neglect the Laplacian, and the mechanism is the same as for the corresponding ordinary differential equation. Our approach allows smaller perturbations of the data, where the instability occurs for times such that the p...

Close to the shielding threshold of synchrotron radiation in a toroidal waveguide the coherent synchrotron radiation (CSR) instability may be driven by a single synchronous mode. The linear analysis of the problem is presented elsewhere. In this paper we study a nonlinear regime of the single-mode CSR instability. We show that in the nonlinear regime the instability is described by a system of ...

The natural frequency and pull-in instability of clamped-clamped nano-actuators in the presence of a dielectric layer are analyzed. The influence of the presence of Casimir force, electrostatic force, fringing field effect, axial force, stretching effects and the size effect are taken into account. The governing equation of the dynamic response of the actuator is transformed in a non-dimensiona...