The Landau-Lifshitz equation of the ferromagnetic spin chain and   Oseen-Frank flow
  In this paper, we consider the Landau-Lifshitz equation of the ferromagnetic spin chain from $\R^2$ to the unit sphere $S^2$ under the general Oseen-Frank energy. We obtain global existence and uniqueness of weak solutions for large energy data; moreover, the number of singular points is finite. 
Xueke Pu, Meng Wang, Wendong Wang
math.AP