Spinning test particle motion around a traversable wormhole

TL;DR

This paper explores how the spin of test particles influences their motion around traversable wormholes, revealing significant effects on the innermost stable circular orbit and considering superluminal constraints.

Contribution

It provides a detailed analysis of spinning particle dynamics around wormholes using the Mathisson Papapetrou-Dixon equations, highlighting the impact of spin on orbital stability and motion constraints.

Findings

Spin significantly shifts the ISCO location compared to nonspinning particles.

Particles with spin parameter less than -1.5 or greater than 1.5 cannot maintain circular orbits at the ISCO.

Spin effects are crucial for understanding Kerr black hole interactions with supermassive wormholes.

Abstract

The motion of spinning test particles around a traversable wormhole is investigated using the Mathisson Papapetrous Dixon equations, which couple the Riemann tensor with the antisymmetric tensor $S^{ab}$, related to the spin of the particle. Hence, we study the effective potential, circular orbits, and innermost stable circular orbit ISCO of spinning particles. We found that the spin affects significantly the location of the ISCO, in contrast with the motion of nonspinning particles, where the ISCO is the same in both the upper and lower universes. On the other hand, since the dynamical fourmomentum and kinematical fourvelocity of the spinning particle are not always parallel, we also consider a superluminal bound on the particles motion. In the case of circular orbits at the ISCO, we found that the motion of particles with an adimensional spin parameter lower greater than $s=-1.5$ $(1.5)$ is forbidden. The spin interaction becomes important for Kerr black hole orbiting super massive wormholes SMWH.