Universality in Relativistic Spinning Particle Models

TL;DR

This paper demonstrates an equivalence among various relativistic spinning particle models, providing a universal framework that encompasses interactions with electromagnetism and gravity, with implications for black hole physics and gravitational wave research.

Contribution

It establishes a model-independent equivalence between different spinning particle models and derives universal equations like BMT and QMPD.

Findings

Models describe the same physics in free and interacting cases.

Derived universal equations for spin dynamics such as BMT and QMPD.

Constructed a gauge-invariant interacting spherical top model.

Abstract

We establish an equivalence between massive spinning particle models in four spacetime dimensions coupled to electromagnetism or gravity, within the spin-magnitude-preserving sector. Four representative models in the literature are shown to describe exactly the same physics in their free and interacting theories: vector oscillator, spinor oscillator, spherical top, and massive twistor. The Bargmann-Michel-Telegdi (BMT) and quadrupolar Mathisson-Papapetrou-Dixon (QMPD) equations are derived in a model-independent fashion. This universal framework allows for incorporating higher spin multipole interactions as well. We establish the rigorous construction of the interacting theory of the spherical top model with emphasis on spin gauge invariance. Applications to black hole physics, conserved charges, and post-Newtonian or post-Minkowskian frameworks are discussed.