Elongation of moving noncommutative solitons

We discuss the characteristic properties of noncommutative solitons moving with constant velocity. As noncommutativity breaks the Lorentz symmetry, th e shape of moving solitons is affected not just by the Lorentz contraction along the velocity direction, but also sometimes by additional 'elongation' transverse to the velocity direction. We explore this in two examples: non commutative solitons in a scalar field theory on two spatial dimension and 'long stick' shaped noncommutative U(2) magnetic monopoles. However the elo ngation factors of these two cases are different, and so not universal. (C) 2000 Published by Elsevier Science B.V.