Sound emission due to superfluid vortex reconnections

By performing numerical simulations based on the Gross-Pitaevskii equation, we make direct quantitative measurements of the sound energy released due to superfluid vortex reconnections. We show that the energy radiated expres sed in terms of the loss of vortex line length is, a simple function of thr reconnection angle. In addition, we study the temporal and spatial distrib ution of the radiation and show that energy is emitted in the form of a sou nd pulse with a wavelength of a few healing lengths.