本文引入δ-黏性上解,δ-黏性下解和δ-黏性解的概念,给出一些相关性质,利用这些性质证明取值于三维单位球面的多维Landau-Lifshitz方程的δ-黏性上解和δ-黏性下解的存在性,揭示存在两个不相交的开子集M和N,使得δ-黏性上解和δ-黏性下解在M内任一紧子集上趋于(0,1,0),在N内任一紧子集上趋于(0,-1,0).
The purpose of this paper is to introduce the concepts of S-viscosity supersolution, δ-viscosity subsolution and δ-viscosity solution, and give their properties, and using these properties prove the existence of δ-viscosity supersolution and δ-viscosity subsolution of the multidimensional Landau-Lifshitz equation with values in a unit sphere, and indicate that there exist two disjoint open subsets M and N such that the δ-viscosity supersolution and δ-viscosity subsolution tend to (0, 1, 0) on arbitrary compact sets in M, and tend to (0,-1, 0) on arbitrary compact sets in N.