Walter Dambrosio

Infinitely many radial solutions to a boundary value problem in a ball

In this paper we are concerned with the existence and multiplicity of radial solutions to the BVP whereB is an open ball in ℝK and u↦∇·(a(|∇u|)∇u) is a nonlinear differential operator (e.g. the plaplacian or the mean curvature operator). The function f is defined in a neighborhood of u=0 and satisfies a «sublinear»-type growth condition for u→0. We use a degree approach combined with a time-map technique. Multiplicity results are obtained also for nonlinearities of concave-convex type.

Multiple solutions of weakly-coupled systems with p-laplacian operators

We prove a multiplicity result for weakly-coupled systems with p-laplacian operators of the form

Scattering Parabolic Solutions for the Spatial N-Centre Problem

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The Maslov Index and Global Bifurcation for Nonlinear Boundary Value Problems

(\phi_{pi}(u_{i}^{\prime}))^{\prime}+gi(u_i)=h_i(t,u,u^\prime),\qquad t\ \in \ (0,1),\qquad

On the boundedness of solutions to a nonlinear singular oscillator

Neumann boundary conditions are assumed and the nonlinearity is supposed to be superlinear asymmetric. We use a topological degree method based on a continuation theorem and on the performance of a time-map technique for the unperturbed case.