Calculus of Variations and Geometric Measure Theory

N. Soave - A. Zilio

On phase separation in systems of coupled elliptic equations: asymptotic analysis and geometric aspects

created by soave on 29 Jul 2015
modified on 07 Dec 2016


Accepted Paper

Inserted: 29 jul 2015
Last Updated: 7 dec 2016

Journal: Annales de l'Institut Henri Poincaré (C) Nonlinear Analysis
Year: 2016
Doi: 10.1016/j.anihpc.2016.04.001
Links: link preliminary version


We consider a family of positive solutions to the system of $k$ components \[ -\Delta u_{i,\beta} = f(x, u_{i,\beta}) - \beta u_{i,\beta} \sum_{j \neq i} a_{ij} u_{j,\beta}^2 \qquad \text{in $\Omega$}, \] where $\Omega \subset \R^N$ with $N \ge 2$. It is known that uniform bounds in $L^\infty$ of $\{\mathbf{u}_{\beta}\}$ imply convergence of the densities to a segregated configuration, as the competition parameter $\beta$ diverges to $+\infty$. In this paper we establish sharp quantitative point-wise estimates for the densities around the interface between different components, and we characterize the asymptotic profile of $\mf{u}_\beta$ in terms of entire solutions to the limit system \[ \Delta U_i = U_i \sum_{j\neq i} a_{ij} U_j^2. \] Moreover, we develop a uniform-in-$\beta$ regularity theory for the interfaces.