Head-on collisions of two concentric ring-shaped dark or antidark solitons
of a generalized nonlinear Schrodinger equation are studied analytically an
d numerically. Collision-induced phase shifts of the solitons are derived,
and the analytical predictions are found to be in good agreement with the r
esults of direct simulations. (C) 2001 Elsevier Science B.V. All rights res
erved.