We deal with a bifurcation result for the Dirichlet problem ⎧ a.e. in Ω, ⎨ ⎩. Starting from a weak lower semicontinuity result by E. Montefusco, which allows us to apply a general variational principle by B. Ricceri, we prove that, for μ close to zero, there exists a positive number such that for every the above problem admits a nonzero weak solution in satisfying .
Using Fan’s Min-Max Theorem we investigate existence of solutions and their dependence on parameters for some second order discrete boundary value problem. The approach is based on variational methods and solutions are obtained as saddle points to the relevant Euler action functional.
Si studiano soluzioni positive dellequazione in , dove , ed è un piccolo parametro positivo. Si impongono in genere condizioni al bordo di Neumann. Quando tende a zero, dimostriamo esistenza di soluzioni che si concentrano su curve o varietà.
We deal with the existence of solutions of the Dirichlet problem for sublinear and superlinear partial differential inclusions considered as generalizations of the Euler-Lagrange equation for a certain integral functional without convexity assumption. We develop a duality theory and variational principles for this problem. As a consequence of the duality theory we give a numerical version of the variational principles which enables approximation of the solution for our problem.
We prove the existence of a positive solution to the BVP imposing some conditions on Φ and f. In particular, we assume to be decreasing in t. Our method combines variational and topological arguments and can be applied to some elliptic problems in annular domains. An bound for the solution is provided by the norm of any test function with negative energy.