Self-force on a charged particle in an external scalar field

TL;DR

This paper explores the self-force experienced by a charged particle in an external scalar field, revealing unique effects like anti-frictional forces and clarifying the distinction between self-force and radiation reaction.

Contribution

It provides a new analysis of self-force in scalar fields, highlighting differences from electromagnetic cases and offering geometric interpretations.

Findings

Self-force can be anti-frictional in scalar fields.

Radiation reaction is not always the dominant self-force.

Spacetime geometry offers insights into radiation without self-force.

Abstract

A charged particle subject to strong external forces will accelerate, and so radiate energy, inducing a self-force. This phenomenon remains contentious, but advances in laser technology mean we will soon encounter regimes where a more complete understanding is essential. The terms "self-force" and "radiation reaction" are often used synonymously, but reflect different aspects of the recoil force. For a particle accelerating in an electromagnetic field, radiation reaction is usually the dominant self-force, but in a scalar field this is not the case, and the total effect of the self-force can be anti-frictional. Aspects of this self-force can be recast in terms of spacetime geometry, and this interpretation illuminates the long-standing enigma of a particle radiating while experiencing no self-force.