Gravitational deflection of light and helicity asymmetry

TL;DR

This paper investigates how gravitational fields from rotating celestial bodies can alter light polarization, leading to helicity asymmetry, which indicates a transfer of spin from the body to photons during scattering.

Contribution

It derives an expression for helicity asymmetry caused by gravitational deflection, highlighting a novel spin transfer mechanism induced by gravity.

Findings

Helicity asymmetry is induced by gravitational deflection.

Spin transfer from rotating bodies to photons is demonstrated.

Theoretical expression for helicity asymmetry is provided.

Abstract

The helicity modification of light polarization which is induced by the gravitational deflection from a classical heavy rotating body, like a star or a planet, is considered. The expression of the helicity asymmetry is derived; this asymmetry signals the gravitationally induced spin transfer from the rotating body to the scattered photons.