Segregated solutions for a class of systems with Lotka-Volterra interaction

TL;DR

This paper constructs segregated positive solutions for a coupled Lotka-Volterra system with small perturbation, showing each component concentrates at different points as the perturbation vanishes, despite the system lacking a variational structure.

Contribution

It introduces a novel method to construct segregated solutions for a non-variational coupled system with critical growth, analyzing different regimes as perturbation tends to zero.

Findings

Solutions concentrate at different critical points of the Robin function.

The system exhibits distinct behaviors in subcritical, critical, and supercritical regimes.

Construction works despite the absence of a variational formulation.

Abstract

This paper deals with the existence of positive solutions to the system $$ -\Delta w_1 - \varepsilon w_1 = \mu_{1} w_1^{p} + \beta w_1 w_2\ \text{in } \Omega,\ -\Delta w_2 - \varepsilon w_2 = \mu_{2} w_2^{p} + \beta w_1 w_2 \ \text{in } \Omega,\ w_1 = w_2 = 0 \ \text{on } \partial \Omega, $$ where $\Omega \subseteq \mathbb{R}^{N}$, $N \ge 4$, $ p ={N+2\over N-2}$ and $ \varepsilon $ is positive and sufficiently small. The interaction coefficient $ \beta = \beta(\varepsilon) \to 0 $ as $ \varepsilon \to 0 $. We construct a family of segregated solutions to this system, where each component blows-up at a different critical point of the Robin function as $\varepsilon \to 0. The system lacks a variational formulation due to its specific coupling form, which leads to essentially different behaviors in the subcritical, critical, and supercritical regimes and requires an appropriate functional settings to carry out the construction.