A Priori Bounds and Multiple Solutions for Superlinear Indefinite Elliptic Problems
✍ Scribed by H. Amann; J. López-Gómez
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 528 KB
- Volume
- 146
- Category
- Article
- ISSN
- 0022-0396
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✦ Synopsis
In this work we study existence and multiplicity questions for positive solutions of second-order semilinear elliptic boundary value problems, where the nonlinearity is multiplied by a weight function which is allowed to change sign and vanish on sets of positive measure. We do not impose a variational structure, thus techniques from the calculus of variations are not applicable. Under various qualitative assumptions on the nonlinearity we establish a priori bounds and employ bifurcation and fixed point index theory to prove existence and multiplicity results for positive solutions. In an appendix we derive interior L p -estimates for general elliptic systems of arbitrary order under minimal smoothness hypotheses. Special instances of these results are used in the derivation of a priori bounds.
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