2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/122392We use the functional representation of Heisenberg-Weyl group and obtain equation for the spectrum of the model, which is more complicated than Bethes ones, but can be written explicitly through theta functions.8 pages, LATEXHigh Energy Physics - TheoryCondensed Mattertext