Geodesic dynamics in brane-de Sitter wormholes

Abstract

We present a dynamical analysis of the null and timelike geodesics around an asymptotically de Sitter wormhole in a Randall-Sundrum brane. In this framework, the wormhole throat is interpreted both as a photon sphere and as a fixed point of the associated dynamical system. The stability of this structure is evaluated using Lyapunov and Jacobi criteria with consistent results. A Bogdanov-Takens bifurcation is observed in the null-geodesic dynamics, highlighting critical changes in the behavior of light around the wormhole. Explicit solutions are derived for geodesics near the throat, providing insight into the optical appearance of the wormhole shadow. These results show qualitatively similar behavior for null and timelike orbits, suggesting universal features of geodesic dynamics in brane-de Sitter wormholes.