We introduce the concept of ring dark solitons in Bose-Einstein condensates. We show that relatively shallow rings are not subject to the snake instability, but a deeper ring splits into a robust ringlike cluster of vortex pairs, which performs oscillations in the radial and azimuthal directions, following the dynamics of the original ring soliton.

part of the Republic Moldova. The artefacts (about 150 items) were discovered in a pit, about 50 cm deep and among them were: two fibulae Röschitz-Sanislău type, seven necklaces, 12 rings, 22 tubes, 23 bracelets, 80 appliqués, coral bead, wild animal tusk pendant 21 amber beads. objects from this deposit are western origin, with known analogues deposits Poland, Hungary, Serbia, Slovakia less Ro...

In recent years, new wearable platforms and peripherals requiring unique modes of interaction have been emerging in record numbers. Watches, necklaces, glasses, even pants [1] are beginning to incorporate technology. Wearable devices also offer many new ways for users to interact; therefore, more research is needed to evaluate these novel methods of interactions. Our research focuses on proposi...

Abstract Wilson loop diagrams are an important tool in studying scattering amplitudes of SYM $N=4$ theory and known by previous work to be associated positroids. In this paper, we study the structure positroids, as well denominator integrand defined each diagram. We give algorithm derive Grassmann necklace positroid directly from diagram, a recursive proof that dimension these cells is thrice n...