On June 27, 2014, at 14:00, in the library of the Institute of Physics Belgrade, Ricardo Carretero (Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, San Diego State University, USA)  presents a seminar talk entitled:

"Vortex rings: nature, physics, mathematics and computations"

Abstract:
In this talk we will explore the beautiful and complex world of vortex rings. A vortex ring is formed when a vortex line (a "twister") is looped back onto itself creating a close ring that carries vorticity. Vortex rings are commonplace in fluids. For example, in liquids, many species of marine mammals know how to create them, play with them and even use them to catch prey! Smoke rings in gases are also common. In fact not only people can make smoke rings, but volcanoes and chimneys are also at it!

We will focus on the occurrence of vortex rings in superfluids (fluids without viscosity) described by the nonlinear Schrödinger equation. We showcase some of their phenomenology including, internal excitation waves (Kelvin modes), their mutual interactions, collisions, and scattering scenarios. We also briefly discuss an efficient computational implementation for solving the ensuing partial differential equations using GPU accelerated codes that allow for numerical integration runs of vortex rings in real time!