2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68857A virtual string is a scheme of self-intersections of a closed curve on a surface. We introduce virtual strings and study their geometric properties and homotopy invariants. We also discuss connections between virtual strings, Gauss words, and virtual knots.30 pages, 1 figureGeometric TopologyAlgebraic Topology57M99text