  We present a theoretical formalism to address the dynamics of textured,
noncolliear antiferromagnets subject to spin current injection. We derive
sine-Gordon type equations of motion for the antiferromagnets, which are
applicable to technologically important antiferromagnets such as Mn3Ir and
Mn3Sn, and enables an analytical approach to domain wall dynamics in those
materials. We obtain the expression for domain wall velocity, which is
estimated to reach around 1 km/s in Mn3Ir by exploiting spin Hall effect with
electric current density around 10^11A/m^2.
