Dynamics of solitons in Bose-condensed gases

Georgy Shlyapnikov

Centre Scientifique d'Orsay, Université Paris-Sud, 15 rue Georges Clémenceau, 91405 Orsay Cedex, France

I will give a brief overview of the studies of soliton structures in Bose-condensed gases, emphasizing an analogy with optical solitons. I then discuss dissipative dynamics of dark (grey) solitons, which can be treated as particle-like objects with a negative mass. Special attention will be focused on the comparison of these objects with relativistic particles and on their non-integrability in quasi-1D geometries.