Chaotic particle dynamics near a traversable wormhole throat

Abstract

This study investigates the nonlinear dynamics of a test particle near the traversable wormhole throat under an external harmonic potential. One-dimensional radial perturbation analysis shows that the particle is locally linearly stable at the equilibrium position. However, for two-dimensional and high-energy cases, the system exhibits a nonlinear response, leading to large-scale chaos. The analysis indicates that, if the particle is confined on one side of the wormhole, the Poincare section will still retain Kolmogorov-Arnold-Moser (KAM) tori under extremely high-energy conditions, which is distinct from the chaos caused by the event horizon in the black hole. By studying another set of shape functions, the universality of this phase space structure is confirmed. This research clarifies the unique nonlinear dynamical mechanism of a traversable wormhole. It provides a new criterion, based on chaotic dynamics, for identifying black hole mimickers in strong-field astrophysical observations.