Axisymmetric flow Eigenvalues and eigenfunctions 6 Gravity waves 6 Arnold's theorem 4 Basic flow 4 Beltrami 4 Beltrami flow 4 Complex topology 4 Eigen-value 4 Enstrophy 4 Euler flows 4 Flow experience 4 Flow structure 4 Force-free magnetic fields 4 Ideal fluids 4 Kelvin waves 4 Magnetic fields 4 Magnetohydrodynamics 4 Stability 4 Topology 4 Variational principles 4 Variational techniques 4 Circular cavity 2 Eigenvalues 2 Governing equations 2 Gravitation 2 Gravity currents 2 Integral curves 2 Liquids 2 Lubrication approximations 2