Universal Thermal Radiation Drag on Neutral Objects

TL;DR

This paper calculates a universal thermal radiation drag force on neutral objects moving through a photon gas, revealing a linear velocity-dependent force rooted in Casimir physics, with implications across various physical contexts.

Contribution

It introduces a new universal Casimir drag force on neutral objects due to thermal radiation, extending understanding of dissipative Casimir effects.

Findings

Drag force is linear in velocity

Force strength varies with dielectric properties

Potential relevance in astrophysics and nanotechnology

Abstract

We compute the force on a small neutral polarizable object moving at velocity $\vec v$ relative to a photon gas equilibrated at a temperature $T$ We find a drag force linear in $\vec v$. Its physical basis is identical to that in recent formulations of the dissipative component of the Casimir force. We estimate the strength of this universal Casimir drag force for different dielectric response functions and comment on its relevance in various contexts.