The goal of the paper is to develop a method that will combine the use of variational
techniques with regularization methods in order to study existence and multiplicity results for …

Given a smooth function $ U (t, x) $, $ T $-periodic in the first variable and satisfying $ U (t,
x)=\mathcal {O}(\vert x\vert^{\alpha}) $ for some $\alpha\in (0, 2) $ as $\vert x\vert\to\infty …

In this paper, by using the Man αsevich-Mawhin theorem on continuity of the topological
degree, we prove the existence of periodic solutions for two classes of second order p …

We prove the existence and multiplicity of periodic solutions of bouncing type for a second-
order differential equation with a weak repulsive singularity. Such solutions can be …

A central force problem in Rd is given by a Newtonian system of the form q=∇ U (q), for
which q∈ Rd, and the force function U (q)∈ C∞(Rd\O, R) is radial, ie depends only on the …