2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34589We present a simple technique for generating new solutions of Einstein's equations using such function transformations that leave the field equations in the Ernst form. In this context we recover all the known covariant transformations of Ernst equations and we find the role of the analytic ones. Finally we obtain a new asymptotically flat solution starting from the Kerr solutions.18 pages, new corrected versionGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext