2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/183067We construct a family of solutions in IIB supergravity theory. These are time dependent or depend on a light-like coordinate and can be thought of as deformations of AdS_5 x S^5. Several of the solutions have singularities. The light-like solutions preserve 8 supersymmetries. We argue that these solutions are dual to the N=4 gauge theory in a 3+1 dimensional spacetime with a metric and a gauge coupling that is varying with time or the light-like direction respectively. This identification allows us to map the question of singularity resolution to the dual gauge theory.13 pages REVTeX and AMSLaTeX. v2: corrected typos and made some clarifications; reference added; v3: more clarifications, references addedHigh Energy Physics - Theorytext