2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34657We investigate the solutions of Einstein equations such that a hedgehog solution is matched to different exterior or interior solutions via a spherical shell. In the case where both the exterior and the interior regions are hedgehog solutions or one of them is flat, the resulting spherical shell becomes a stringy shell. We also consider more general matchings and see that in this case the shell deviates from its stringy character.11 pagesGeneral Relativity and Quantum Cosmologytext