Document Type

Article

Department

Mathematics (HMC)

Publication Date

1-1997

Abstract

We consider the positive solutions to the semilinear equation:

-Δu(x) = λf(u(x)) for x ∈ Ω

u(x) = 0 for x ∈ ∂Ω

where Ω denotes a smooth bounded region in RN (N > 1) and λ > 0. Here f :[0, ∞)→R is assumed to be monotonically increasing, concave and such that f(0) < 0 (semipositone). Assuming that f'(∞) ≡ lim t→∞ f'(t) > 0, we establish the stability and uniqueness of large positive solutions in terms of (f(t)/t)'. When Ω is a ball, we determine the exact number of positive solutions for each λ > 0. We also obtain the geometry of the branches of positive solutions completely and establish how they evolve. This work extends and complements that of [3, 7] where f'(∞) ≤ 0.

Comments

Archived with permission from the Royal Society of Edinburgh.

Note: The DOI link in the document is not correct (it has an extra 0). The DOI link below on this page is correct.

Rights Information

© 1997 Royal Society of Edinburgh

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