We present the first unrestricted, three-dimensional relativistic hydrodynamical calculations of the blob of gas associated with the jet producing a gamma-ray burst. We investigate the deceleration phase of the blob corresponding to the time when afterglow radiation is produced, concentrating on the transition in which the relativistic beaming γ goes from being less than θ, where γ is the bulk ...

A review is given on the theory of vortex-glass phases in impure type-II superconductors in an external field. We begin with a brief discussion of the effects of thermal fluctuations on the spontaneously broken U (1) and translation symmetries, on the global phase diagram and on the critical behaviour. Introducing disorder we restrict ourselves to the experimentally most relevant case of weak u...

We consider a special configuration of vorticity that consists of a pair of externally tangent circular vortex sheets, each having a circularly symmetric core of bounded vorticity concentric to the sheet, and each core precisely balancing the vorticity mass of the sheet. This configuration is a stationary weak solution of the 2D incompressible Euler equations. We propose to perform numerical ex...

This paper addresses vision-based people counting under the assumption of an oblique stationary camera setup without any usage of tracking. Our approach is based on motion detection and blob analysis. The estimation of the number of people in the scene is done by accumulating the estimation values of each blob. The blob specific estimation values are computed using four input values: the minimu...

Plasma blob dynamics on the high-field side in the proximity of a magnetic field null (X point) is investigated in TORPEX. A significant acceleration of the blobs towards the X point is observed. Close to the X point the blobs break apart. The E×B drifts associated with the blobs are measured, isolating the background drift component from the fluctuating contribution of the blob internal potent...

We report the results of large scale numerical studies of the dynamic and static properties of the random phase model of the randomly pinned flux lines confined in a plane. From the onset of nonlinear IV characteristics, we identify a vortex glass transition at the theoretically anticipated temperature. However, the vortex glass phase itself is much less glassy than expected. No signature of th...

The striate cortex of macaque monkeys contains an array of patches which stain heavily for the enzyme cytochrome oxidase (CO blobs). Cells inside and outside these blobs are often described as belonging to two distinct populations or streams. In order to better understand the function of the CO blobs, we measured the contrast sensitivity and spatial frequency response of single neurons in and a...

We study the interplay between Dirac eigenmodes and center vortices in SU(2) lattice gauge theory. In particular we focus on vortex-removed configurations and compare them to an ensemble of configurations with random changes of the link variables. We show that removing the vortices destroys all zero modes and the near zero modes are no longer coupled to topological structures. The Dirac spectru...

We numerically study the topology of optical vortex lines (nodal lines) in volumes of optical speckle, modeled as superpositions of random plane waves. It is known that the vortex lines may be infinitely long, or form closed loops. Loops are occasionally threaded by infinite lines, or linked with other loops. We find the probability of a loop not being threaded decays exponentially with the len...

We study the formation of vortices in a U(1) gauge theory following a firstorder transition proceeding by bubble nucleation, in particular the effect of a low velocity of expansion of the bubble walls. To do this, we use a twodimensional model in which bubbles are nucleated at random points in a plane and at random times and then expand at some velocity vb < c. Within each bubble, the phase ang...