2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/35706In the present work we show that the Einstein equations on $M$ without cosmological constant and with perfect fluid as source, can be obtained from the field equations for vacuum with cosmological constant on the principal fibre bundle $P(\frac{1}{I} M,U(1))$, $M$ being the space-time and $I$ the radius of the internal space $U(1)$.7 pages, Latex, 0 figuresGeneral Relativity and Quantum Cosmologytext