Dynamics of kinks in a traversable wormhole

Abstract

We investigate the dynamics of spherically symmetric radial domain walls (or kinks) in a traversable Simpson-Visser wormhole. By solving the scalar field in a double-well potential, we find that the parameter $a$ has a strong impact on the kink dynamics: larger $a$ allows the kink to go through the throat back and forth, while smaller $a$ strongly confines the kink nearby the throat. In addition, each traverse of the kink through the throat is accompanied with the emission of scalar wave packets, resulting in a gradual decrease of the oscillation amplitude reminiscent of a damping oscillator. This oscillatory behavior between the two sides of the wormhole is in sharp contrast to its counterpart in compact objects, such as boson stars. Our findings uncover how wormhole geometry will influence the dynamics of topological defects and may provide new insights for distinguishing wormholes from ordinary compact objects.