### On the asymptotic behavior of the solutions of the Landau-Lifshitz equation

Takeshi Isobe

#### Abstract

Let $\Omega\subset\Bbb{R}^2$ be a bounded domain and $H\in\Bbb{R}^3$. The Landau-Lifshitz equation with external field $H$ and boundary data $\gamma\in C^{\infty}(\partial\Omega;\Bbb{S}^2)$ is the following: $$\Delta u+|\nabla u|^2u-(H,u)u+H=0\quad\text{in \Omega},\quad u=\gamma\quad\text{on \partial\Omega}.$$ Here $u\in C^{\infty}(\Omega;\Bbb{S}^2)$. We study the asymptotic behavior of the solutions of this equation as $H\to 0$. We show that the "large solutions" obtained by Hong and Lemaire blow up only when $\gamma\equiv\text{const.}$ and in such a case blow-up occurs only at a single point in $\Omega$. We characterize the blow-up point as a critical point of a certain function defined in $\Omega$. We also give the asymptotic value estimate of $\|\nabla u\|_{{L^{\infty}(\Omega)}}$ as $H\to 0$.

#### Article information

Source
Adv. Differential Equations Volume 5, Number 7-9 (2000), 1033-1090.

Dates
First available in Project Euclid: 27 December 2012

Mathematical Reviews number (MathSciNet)
MR1776348

Zentralblatt MATH identifier
1223.35155

#### Citation

Isobe, Takeshi. On the asymptotic behavior of the solutions of the Landau-Lifshitz equation. Adv. Differential Equations 5 (2000), no. 7-9, 1033--1090.https://projecteuclid.org/euclid.ade/1356651294