Loitering at the hilltop on exterior domains

In this paper we prove the existence of an infinite number of radial solutions of $\Delta u + f(u)= 0$ on the exterior of the ball of radius $R>0$ centered at the origin and $f$ is odd with $f<0$ on $(0, \beta) $, $f>0$ on $(\beta, \delta),$ and $f\equiv 0$ for $u> \delta$. The primitive...

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Bibliographic Details
Main Author: Joseph Iaia
Format: Article
Language:English
Published: University of Szeged 2015-11-01
Series:Electronic Journal of Qualitative Theory of Differential Equations
Subjects:
Online Access:http://www.math.u-szeged.hu/ejqtde/periodica.html?periodica=1&paramtipus_ertek=publication&param_ertek=4163
Description
Summary:In this paper we prove the existence of an infinite number of radial solutions of $\Delta u + f(u)= 0$ on the exterior of the ball of radius $R>0$ centered at the origin and $f$ is odd with $f<0$ on $(0, \beta) $, $f>0$ on $(\beta, \delta),$ and $f\equiv 0$ for $u> \delta$. The primitive $F(u) = \int_{0}^{u} f(t) \, dt$ has a "hilltop" at $u=\delta$ which allows one to use the shooting method and ODE techniques to prove the existence of solutions.
ISSN:1417-3875