In the Taylor-Couette experiment on fluid flow between counterrotating cylinders, there is a bicritical point where the onset of instabilities to Taylor vortex flow (a steady-state bifurcation) and spiral vortex flow (a Hopf bifurcation) meet. The nonlinear mode interactions near this bicritical point are analyzed, exploiting the role of symmetry in the bifurcation theory. and with emphasis on ...

The studies of standard and neoclassical tearing instabilities in experimental tokamak plasmas show that these modes can be a serious problem on the path toward magnetic fusion. A precise understanding of their dynamics therefore is crucial, but requires full toroidal extended magneto-hydrodynamic (MHD) simulations. Solving this problem is difficult, both from the point of view of the extreme p...

Suspensions of active particles, such as motile microorganisms and artificial microswimmers, are known to undergo a transition to complex large-scale dynamics at high enough concentrations. While a number of models have demonstrated that hydrodynamic interactions can in some cases explain these dynamics, collective motion in experiments is typically observed at such high volume fractions that s...

LLE Review, Volume 80 185 In inertial confinement fusion (ICF), a spherical shell filled with a DT-gas mixture is compressed to high densities and temperatures to achieve ignition condition.1 Degradation from spherical symmetry during the implosion, however, limits the achievable compression ratios and could quench the ignition. The main source of such asymmetry is hydrodynamic instabilities (s...

Ideal hydrodynamic models of the intracluster medium (ICM) in the core regions of galaxy clusters fail to explain both the observed temperature structure of this gas, and the observed morphology of radio-galaxy/ICM interactions. It has recently been suggested that, even in the presence of reasonable magnetic fields, thermal conduction in the ICM may be crucial for reproducing the temperature fl...

A check is made of a stabilization theorem of ROSENBLUTH and KRALL (Phys. Fluids 8, 1004 [1965]) according to which an inhomogeneous plasma in a minimum-ß field {ß 1) should be stable with respect to electrostatic drift instabilities when the particle distribution functions satisfy a condition given by TAYLOR, i. e. when AND ^fl^W <L 0. Although the dispersion relation of ROSENBLUTH and KRALL i...