Motion of Spin 1/2 Massless Particle in a Curved Spacetime. I. Lagrangian Approach

TL;DR

This paper develops a Lagrangian model for the quasi-classical motion of massless spin 1/2 particles in curved spacetime, aligning with Papapetrou equations for photon dynamics.

Contribution

It introduces a simple Lagrangian framework for massless spin 1/2 particles, extending classical equations of motion to this context.

Findings

Equations of motion match Papapetrou equations for photons.

Provides a Lagrangian approach for massless spin 1/2 particles.

Establishes a basis for further quantum-classical correspondence.

Abstract

Quasi-classical picture of motion of spin 1/2 massless particle in a curved spacetime is built on base of simple Lagrangian model. The one is constructed due to analogy with Lagrangian of massive spin 1/2 particle. Equations of motion and spin propagation coincide with Papapetrou equations describing dynamic of photon in a curved spacetime.