Fully covariant radiation force on a polarizable particle

TL;DR

This paper develops a fully covariant relativistic framework to calculate electromagnetic radiation forces on polarizable particles, incorporating local thermal equilibrium and illustrating with examples like background radiation and interfaces.

Contribution

It introduces a covariant formulation of electromagnetic forces on particles, unifying previous results and enabling analysis of relativistic effects in radiation pressure and friction.

Findings

Derived a covariant expression for radiation force

Recovered previous results for arbitrary velocities

Illustrated with examples of particles near interfaces

Abstract

The electromagnetic force on a polarizable particle is calculated in a covariant framework. Local equilibrium temperatures for the electromagnetic field and the particle's dipole moment are assumed, using a relativistic formulation of the fluctuation-dissipation theorem. Two examples illustrate radiative friction forces: a particle moving through a homogeneous radiation background and above a planar interface. Previous results for arbitrary relative velocities are recovered in a compact way.