Sitter School Brane Gauge Invariant Fluctuations

This project aims to extend the formalism developed by J. M. Bardeen, originally applied to theories with a simple scalar field and self-interaction potential, to the context of De-Sitter scalar branes. The interest lies in brane-world scenarios (gravitational theories with 4+1 extra dimensions) where stable domain walls induce standard gravitational interaction in the 4D sector. The main objective is to re-examine the spectrum of gravitational perturbations associated with these topological defects. The methodology will focus on rewriting the metric perturbation modes in terms of gauge-invariant variables, following and generalizing procedures detailed in previous references concerning the application of Bardeen's formalism to static scalar branes. This approach is expected to provide a more robust description of the gravitational spectrum in these models.<br/><br/><b>Goal</b>: <br/>Generalize J. M. Bardeen's formalism to the case of De-Sitter scalar branes to examine the spectrum of associated gravitational perturbations using gauge-invariant variables.<br/><br/><b>Research lines</b>: <br/>Analysis, development and improvement of materials, tools and techniques for use in construction, industry and various applications