The phenomenon of vortex reconnection is analysed numerically and the results are compared qualitatively with the predictions of a model of reconnection recently proposed by Saffman. Using spectral methods over both uniform and strained meshes, numerical simulations are performed of two nearly parallel, counter-rotating vortex tubes, over the range of Reynolds numbers Re = 1000-3500. The calcul...

An isolated critical point is a peculiar thermodynamic that occurs in the phase diagram of hyperbolic black holes Kth-order Lovelock gravity higher dimensions (with K odd) for special tuned coupling constants. It corresponds to "merger" two swallowtails and characterized by non-standard exponents. Upon employing recent proposal assigning topological charge points, we argue offers an interpretat...

Granular vortex structures (swirling motion of several grains around its central point) were frequently observed in experiments on granular materials and in calculations using the discrete element method (DEM). They became apparent when the motion associated with uniform (affine) strain was subtracted from the actual granular deformation. The dominant mechanism responsible for the vortex format...

A bstract We use holography to investigate the dynamics of a vortex-anti-vortex dipole in strongly coupled superfluid 2+1 dimensions. The system is evaluated numerical real-time simulations order study evolution vortices as they approach and eventually annihilate each other. tracking algorithm with sub-plaquette resolution introduced which permits high-precision determination vortex trajectorie...

We have combined a novel low temperature positioning mechanism with a single-chip miniature superconducting quantum interference device ~SQUID! magnetometer to form an extremely sensitive new magnetic microscope, with a demonstrated spatial resolution of ;10 mm. The design and operation of this scanning SQUID microscope will be described. The absolute calibration of this instrument with an idea...

We report an experiment that uses a superfluid helium quantum interference device to probe the initial onset of the motion of a single vortex line driven by axial flow in a macroscopic channel. When the superfluid velocity reaches a temperature independent critical value !vc#1 mm/s" periodic 2! phase slippage occurs with a frequency of the order of a few Hz. As the axial flow velocity increases...