2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/225071In this text we investigate the good behaviour of the elementary obstruction, introduced by Colliot-Thelene and Sansuc. This is an obstruction to the existence of a rational points on certain algebraic varieties. Assuming some conditions on the Picard group, we prove that the elementary obstruction behaves well under the Weil restriction of a variety.9 pages, revised version for publicationAlgebraic GeometryNumber Theory14G05; 11G99text