Guerrero Román, MercedesOlmo, Gonzalo J.Rubiera García, Diego2024-04-152024-04-152023-09-071434-604410.1140/epjc/s10052-023-11969-yhttps://hdl.handle.net/20.500.14352/1031082023 Descuento SCOAPWe study the completeness of light trajectories in certain spherically symmetric regular geometries found in Palatini theories of gravity threaded by non-linear (electromagnetic) fields, which makes their propagation to happen along geodesics of an effective metric. Two types of geodesic restoration mechanisms are employed: by pushing the focal point to infinite affine distance, thus unreachable in finite time by any sets of geodesics, or by the presence of a defocusing surface associated to the development of a wormhole throat. We discuss several examples of such geometries to conclude the completeness of all such effective paths. Our results are of interest both for the finding of singularity-free solutions and for the analysis of their optical appearances e.g. in shadow observations.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article1434-6052https://link.springer.com/article/10.1140/epjc/s10052-023-11969-yopen access539.1PhotonsShadowHolePartículas2212.02 Partículas Elementales