Implicit elliptic boundary-value problems with discontinuous nonlinearities

Let be a bounded domain in ⁿ (n3) having a smooth boundary, let be an essentially bounded real-valued function defined on × ^h, and let be a continuous real-valued function defined on a given subset Y of Y ^h. In this paper, the existence of strong solutions u W ^2,p (, ^h) W _o ^1,p (n/2<p<+) to the implicit elliptic equation (–u)=(x,u), with u=(u₁, u₂, ..., u_h) and u=(u ₁, u ₂, ..., u _h), is established. The abstract framework where the problem is placed is that of set-valued analysis.     

On nonlinear elliptic problems with jumping nonlinearities

Summary Elliptic equations with nonlinearities, which have different derivatives at plus and minus infinity, are studied. A characterization of solvability is given by establishing the existence of nonlinear eigenvalues of a corresponding positive-homogeneous equation.     

Solutions of elliptic problems with nonlinearities of linear growth

In this paper, we study existence of nontrivial solutions to the elliptic equation

On a class of elliptic problems with indefinite nonlinearities

In this paper we apply variational and sub-supersolution methods to study the existence and multiplicity of nonnegative solutions for a class of indefinite semilinear elliptic problems that depend on a parameter. The results on the existence of solutions do not impose any growth condition at infinity on the term which depends on the parameter. To derive such results, first we find a positive supersolution by solving an auxiliary problem. Then we use a truncation argument and a global minimization method. The main hypothesis for the existence of two nonzero solutions is that the indefinite term is the product of a weight function, having a thick zero set, and a nonlinear function which satisfies the Ambrosetti–Rabinowitz superlinear condition. Results for some corresponding indefinite problems are also established.     

Singularly perturbed elliptic problems with superlinear or asymptotically linear nonlinearities

We consider a class of equations of the form By variational methods, we show the existence of families of positive solutions concentrating around local minima of the potential V(x), as . We do not require uniqueness of the ground state solutions of the associated autonomous problems nor the monotonicity of the function . We deal with asymptotically linear as well as superlinear nonlinearities.Received: 8 November 2003, Accepted: 18 November 2003, Published online: 2 April 2004Mathematics Subject Classification (2000): 35B25, 35J65, 58E05     

Multiplicity results for semilinear resonant elliptic problems with discontinuous nonlinearities

In the present paper, some generalized critical points theorems for locally Lipschitz functions are given; as applications, some multiplicity results for zero-boundary-value elliptic resonant problems are obtained. Two classical important theorems are improved.     

Non-differentiable functionals and applications to elliptic problems with discontinuous nonlinearities

Multiple critical points theorems for non-differentiable functionals are established. Applications both to elliptic variational-hemivariational inequalities and eigenvalue problems with discontinuous nonlinearities are then presented.     

Nondegeneracy of elliptic problems with periodic nonlinearities in the plane

A class of asymptotically quadratic functionals on Hilbert spaces, called degenerate, is considered and explored. Our results are applied to obtain a extension, in the planar case, of a result published by Solimini in ‘On the solvability of some elliptic partial differential equations with the linear part at resonance’, J. Math. Anal. Appl., 117 (1986), 138-152. Similar extensions had been previously studied in the literature only for domains with particular geometries.     

Bifurcation problems for equations of elliptic type with discontinuous nonlinearities

We consider the problem of the existence of semiregular solutions to the main boundary-value problems for second-order equations of elliptic type with a spectral parameter and discontinuous nonlinearities. A variational method is used to obtain the theorem on the existence of solutions and properties of the “separating” set for the problems under consideration. The results obtained are applied to the Goldshtik problem.     

Bifurcation from the essential spectrum for an elliptic equation with general nonlinearities

In this paper, based on some prior estimates, we show that the essential spectrum λ = 0 is a bifurcation point for a superlinear elliptic equation with only local conditions, which generalizes a series of earlier results on an open problem proposed by Stuart(1983).     

Indefinite quasilinear elliptic problems with subcritical and supercritical nonlinearities on unbounded domains

By using the fibering method, we study the existence of non-negative solutions for a class of indefinite quasilinear elliptic problems on unbounded domains with noncompact boundary, in the presence of competing subcritical and supercritical lower order nonlinearities.     

Existence and multiplicity of solutions for elliptic problems with indefinite discontinuous nonlinearities

In this paper we study the critical points for a locally Lipschitz functional that in some sense will be solutions of an elliptic problem with indefinite discontinuous nonlinearities. We should mention that our results were inspired by the work of Ambrosetti-Badiale [3], Arcoya-Calahorrano [5], Alama-Tarantello [1] and Chang [8]. For the problem studied in [3] we introduce indefinite nonlinearities as in [1] and [6]. To obtain the existence and multiplicity of solutions we use the critical points theory developed by Chang. Applications for Plasma Physics are considered with nonlinearities that change sign. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A variational approach to singular quasilinear elliptic problems with sign changing nonlinearities

We obtain positive solutions of singular p-Laplacian problems with sign changing nonlinearities using variational methods.     

Multiple solution results for elliptic Neumann problems involving set-valued nonlinearities

The main goal of this paper is to present multiple solution results for elliptic inclusions of Clarke's gradient type under nonlinear Neumann boundary conditions involving the p-Laplacian and set-valued nonlinearities. To be more precise, we study the inclusion