Language:   Search:   Contact
Zentralblatt MATH has released its new interface!
For an improved author identification, see the new author database of ZBMATH.

Query:
Fill in the form and click »Search«...
Format:
Display: entries per page entries
Zbl 0647.35031
Shivaji, Ratnasingham
A remark on the existence of three solutions via sub-super solutions.
(English)
[A] Nonlinear analysis and applications, Proc. 7th Int. Conf., Arlington/Tex. 1986, Lect. Notes Pure Appl. Math. 109, 561-566 (1987).

Summary: [For the entire collection see Zbl 0632.00014.] \par We prove that if there exists a sub solution $\psi\sb 1$, a strict super solution $\phi\sb 1$, a strict sub solution $\psi\sb 2$, and a super solution $\phi\sb 2$ for $$(1.1)\quad Lu(x)=-\Delta u(x)+qu(x)=f(x,u(x));\quad x\in \Omega,$$ $$(1.2)\quad Bu(x)=u(x)=0;\quad x\in \partial \Omega,$$ such that $\psi\sb 1<\phi\sb 1<\phi\sb 2$, $\psi\sb 1<\psi\sb 2<\phi\sb 2$ and $\psi\sb 2\nleq \phi\sb 1$, then (1.1)-(1.2) has at least three distinct solutions $u\sb s$ $(s=1,2,3)$ such that $\psi\sb 1\le u\sb 1<u\sb 2<u\sb 3\le \phi\sb 2$. (Here we write $z\sb 1<z\sb 2$ when $z\sb 1\le z\sb 2$ and $z\sb 1\ne z\sb 2.)$ This extends the work by {\it H. Amann} [SIAM Review 18, 620- 709 (1976; Zbl 0345.47044)] where the case $\psi\sb 1<\phi\sb 1<\psi\sb 2<\phi\sb 2$ was studied.
MSC 2000:
*35J65 (Nonlinear) BVP for (non)linear elliptic equations
35A05 General existence and uniqueness theorems (PDE)
35B35 Stability of solutions of PDE

Keywords: existence; multiplicity; sub solution; super solution

Citations: Zbl 0632.00014; Zbl 0345.47044

Highlights
Master Server