Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$

Let $D$ be an unbounded domain in $mathbb{R}^{n}$ ($ngeq 2$) with a nonempty compact boundary $partial D$. We consider the following nonlinear elliptic problem, in the sense of distributions, $$displaylines{ Delta u=f(.,u),quad u>0quad hbox{in }D,cr uig|_{partial D}=alpha varphi ,cr lim_{|x|o +...

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Main Authors: Faten Toumi, Noureddine Zeddini
Format: Article
Language:English
Published: Texas State University 2005-12-01
Series:Electronic Journal of Differential Equations
Subjects:
Online Access:http://ejde.math.txstate.edu/Volumes/2005/143/abstr.html
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author Faten Toumi
Noureddine Zeddini
author_facet Faten Toumi
Noureddine Zeddini
author_sort Faten Toumi
collection DOAJ
description Let $D$ be an unbounded domain in $mathbb{R}^{n}$ ($ngeq 2$) with a nonempty compact boundary $partial D$. We consider the following nonlinear elliptic problem, in the sense of distributions, $$displaylines{ Delta u=f(.,u),quad u>0quad hbox{in }D,cr uig|_{partial D}=alpha varphi ,cr lim_{|x|o +infty }frac{u(x)}{h(x)}=eta lambda , }$$ where $alpha ,eta,lambda $ are nonnegative constants with $alpha +eta >0$ and $varphi $ is a nontrivial nonnegative continuous function on $partial D$. The function $f$ is nonnegative and satisfies some appropriate conditions related to a Kato class of functions, and $h$ is a fixed harmonic function in $D$, continuous on $overline{D}$. Our aim is to prove the existence of positive continuous solutions bounded below by a harmonic function. For this aim we use the Schauder fixed-point argument and a potential theory approach.
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spelling doaj.art-55415508c4cf48168bf5e18b43928d672022-12-21T19:40:50ZengTexas State UniversityElectronic Journal of Differential Equations1072-66912005-12-012005143114Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$Faten ToumiNoureddine ZeddiniLet $D$ be an unbounded domain in $mathbb{R}^{n}$ ($ngeq 2$) with a nonempty compact boundary $partial D$. We consider the following nonlinear elliptic problem, in the sense of distributions, $$displaylines{ Delta u=f(.,u),quad u>0quad hbox{in }D,cr uig|_{partial D}=alpha varphi ,cr lim_{|x|o +infty }frac{u(x)}{h(x)}=eta lambda , }$$ where $alpha ,eta,lambda $ are nonnegative constants with $alpha +eta >0$ and $varphi $ is a nontrivial nonnegative continuous function on $partial D$. The function $f$ is nonnegative and satisfies some appropriate conditions related to a Kato class of functions, and $h$ is a fixed harmonic function in $D$, continuous on $overline{D}$. Our aim is to prove the existence of positive continuous solutions bounded below by a harmonic function. For this aim we use the Schauder fixed-point argument and a potential theory approach.http://ejde.math.txstate.edu/Volumes/2005/143/abstr.htmlGreen functionnonlinear elliptic equationpositive solutionSchauder fixed point theorem.
spellingShingle Faten Toumi
Noureddine Zeddini
Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$
Electronic Journal of Differential Equations
Green function
nonlinear elliptic equation
positive solution
Schauder fixed point theorem.
title Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$
title_full Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$
title_fullStr Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$
title_full_unstemmed Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$
title_short Existence of positive solutions for nonlinear boundary-value problems in unbounded domains of $mathbb{R}^{n}$
title_sort existence of positive solutions for nonlinear boundary value problems in unbounded domains of mathbb r n
topic Green function
nonlinear elliptic equation
positive solution
Schauder fixed point theorem.
url http://ejde.math.txstate.edu/Volumes/2005/143/abstr.html
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