2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/225762Starting from a 5D Riemann flat metric, we have induced an effective 4D Hermitian metric which has an antisymmetric part which is purely imaginary. We have worked an example in which both, non-metricity and contorsion are zero. We obtained that the production of monopoles should be insignificant at the end of inflation and the tensor metric should come asymptotically diagonal and describing a nearly 4D de Sitter expansion.Version accepted in Physics Letters BGeneral Relativity and Quantum Cosmologytext