  We study current-induced dynamics of spin textures in thin magnetic
nanowires. We derive effective equations of motion describing the dynamics of
the domain-wall soft modes associated with topological defects. Because the
magnetic domain walls are topological objects, these equations are universal
and depend only on a few parameters. We obtain spin spiral domain-wall
structure in ferromagnetic wires with Dzyaloshinskii-Moriya interaction and
critical current dependence on this interaction. We also find the most
efficient way to move the domain walls by resonant current pulses and propose a
procedure to determine their dynamics by measuring the voltage induced by a
moving domain wall. Based on translationally non-invariant nanowires, we show
how to make prospective magnetic memory nanodevices much more energy efficient.
