RAPHAËL CÔTE AND RADU IGNAT
A. We consider a ferromagnetic nanowire and we focus on an asymptotic regime where the Dzyaloshinskii-Moriya interaction is taken into account.First we prove a dimension reduction result via Γ-convergence that determines a limit functional defined for maps : R → S 2 in the direction 1 of the nanowire. The energy functional is invariant under translations in 1 and rotations about the axis 1 . We fully classify the critical points of finite energy when a transition between − 1 and 1 is imposed; these transition layers are called (static) domain walls.The evolution of a domain wall by the Landau-Lifshitz-Gilbert equation associated to under the effect of an applied magnetic field ℎ( ) 1 depending on the time variable gives rise to the so-called precessing domain wall. Our main result proves the asymptotic stability of precessing domain walls for small ℎ in ∞ ([0, +∞)) and small 1 (R) perturbations of the static domain wall, up to a gauge which is intrinsic to invariances of the functional .