Dirac equations in curved space-time versus Papapetrou spinning particles

TL;DR

This paper derives classical spinning particle equations from Dirac quantum fields in curved spacetime, establishing a fundamental link between quantum and classical descriptions of spin-gravity coupling.

Contribution

It demonstrates how classical spinning particle equations can be obtained from quantum Dirac fields using an eikonal approximation, bridging quantum and classical spin interactions with gravity.

Findings

Recovered Mathisson-Papapetrou equations from quantum Dirac fields.

Established a fundamental correspondence between quantum and classical spin-gravity coupling.

Validated the classical limit of quantum spin interactions in curved spacetime.

Abstract

We find out classical particles, starting from Dirac quantum fields on a curved space-time, by an eikonal approximation and a localization hypothesis for amplitudes. We recover the results by Mathisson-Papapetrou, hence establishing a fundamental correspondence between the coupling of classical and quantum spinning particles with the gravitational field.