Mean-field model of interaction between bright vortex solitons in Bose-Einstein condensates

Using the explicit numerical solution of the axially symmetric Gross Pitaevskii equation we study the dynamics of interaction among vortex solitons in a rotating matter-wave bright soliton train in a radially trapped and axially free Bose - Einstein condensate to understand certain features of the experiment by Strecker et al ( 2002 Nature 417 150). In a soliton train, solitons of opposite phase (phase delta = pi) repel and stay apart without changing shape; solitons with delta = 0 attract, interact and coalesce, but eventually come out; solitons with a general delta usually repel but interact inelastically by exchanging matter. We study this and suggest future experiments with vortex solitons.