2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/193667We construct a minimal example of a supersymmetric grand unified model in a toroidal compactification of type I string theory with magnetized D9-branes. All geometric moduli are stabilized in terms of the background internal magnetic fluxes which are of "oblique" type (mutually non-commuting). The gauge symmetry is just SU(5) and the gauge non-singlet chiral spectrum contains only three families of quarks and leptons transforming in the $10+{\bar 5}$ representations.48 pagesHigh Energy Physics - TheoryHigh Energy Physics - Phenomenologytext