Abstract
It is shown that under certain geometrical assumptions on a domain any positive solution of △u+f(u)=0 in D, u=0 on ∂D has level Sets with the same geometrical properties as D. This implies that u has only one critical point and externds results of PAYNE1 and SPERß2.
†This research was supported in part by the Deutsche Forschunesemeinschaft.
†This research was supported in part by the Deutsche Forschunesemeinschaft.
Notes
†This research was supported in part by the Deutsche Forschunesemeinschaft.