Regularized variational principles for the perturbed Kepler problem Barutello, Vivina Ortega, Rafael Verzini, Gianmaria 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 the periodic and the Dirichlet problem associated to the perturbed Kepler system. The existence of critical points for the action functional associated to the problem is proved via a non-local change of variables inspired by Levi-Civita and Kustaanheimo-Stiefel techniques. As an application we will prove that the perturbed Kepler problem has infinitely many generalized T-periodic 2025-01-16T07:00:23Z 2025-01-16T07:00:23Z 2021 journal article https://doi.org/10.1016/j.aim.2021.107694 https://hdl.handle.net/10481/99290 https://doi.org/10.1016/j.aim.2021.107694 eng open access Elsevier