ISSN:
1618-1891
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mathematics
Notes:
Summary This paper treats nonlinear elliptic boundary value problems of the form $$\Delta u + f(x,u) = 0in\Omega ,u = 0on\partial \Omega $$ in the spaceL 2(Ω) by degree theoretic methods. Emphasis is placed on existence of multiplesolutions in the case, where the nonlinearity f crosses several eigenvalues of the correspondingeigenvalue problem Δθ+λθ = 0 with zero boundary values. No differentiability conditions(but Lipschitz type conditions) on f are assumed. A main tool is a new a priori bound forsolutions (Theorem 1). The method is not confined to the selfadjoint case. It applies alsoto some time-periodic parabolic and hyperbolic problems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01769219