Electronic Journal of Differential Equations (Dec 2011)
Existence of positive solutions for semilinear elliptic systems with indefinite weight
Abstract
This article concerns the existence of positive solutions of semilinear elliptic system $$displaylines{ -Delta u=lambda a(x)f(v),quadhbox{in }Omega,cr -Delta v=lambda b(x)g(u),quadhbox{in }Omega,cr u=0=v,quad hbox{on } partialOmega, }$$ where $Omegasubseteqmathbb{R}^N (Ngeq1)$ is a bounded domain with a smooth boundary $partialOmega$ and $lambda$ is a positive parameter. $a, b:Omegaomathbb{R}$ are sign-changing functions. $f, g:[0,infty)omathbb{R}$ are continuous with $f(0)>0$, $g(0)>0$. By applying Leray-Schauder fixed point theorem, we establish the existence of positive solutions for $lambda$ sufficiently small.