The time-evolution equations for an isolated domain in an excitable reaction-diffusion system are derived both in two and three dimensions by an interfacial approach near the drift bifurcation where a motionless state becomes unstable and a domain starts propagation at a certain velocity. The coupling between shape deformation of domain and the migration velocity is taken into consideration. When the relaxation of shape deformation is slow enough, a straight motion becomes unstable and several kinds of motion of domain appear depending on the parameters. The self-propelled domain dynamics under the external fields is also studied.
Digital Object Identifier: 10.2969/aspm/06410137