2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/189416We show that the vacuum state functional for both open and closed string field theories can be constructed from the vacuum expectation values it must generate. The method also applies to quantum field theory and as an application we give a diagrammatic description of the equivalance between Schrodinger and covariant repreresentations of field theory.15 pages, 35 .eps figuresHigh Energy Physics - Theorytext