Finite size corrections to the radiation reaction force in classical electrodynamics

Area of Science:

• Theoretical physics
• Electromagnetism
• Particle physics

Background:

• Existing models often approximate finite-sized charged objects as point particles.
• This approximation can lead to inaccuracies when considering electromagnetic interactions.
• Previous literature frequently suggested linear (R) scaling for finite size effects.

Purpose of the Study:

• To develop a robust theoretical framework for describing the electromagnetic interactions of finite-sized objects.
• To rigorously determine the correct scaling of finite size effects in these interactions.
• To calculate the leading order finite size correction to the Abraham-Lorentz-Dirac force.

Main Methods:

• Introduction of an effective field theory (EFT) approach.
• Application of Poincaré and gauge symmetry principles.
• Derivation of scaling laws for finite object radius (R).

Main Results:

• Demonstration that leading order finite size effects scale as R-squared (R^2).
• Proof that linear (R) corrections are excluded by fundamental symmetries.
• Calculation of the leading order finite size correction to the Abraham-Lorentz-Dirac force.

Conclusions:

• The effective field theory provides a more accurate description of finite size object dynamics.
• The R-squared scaling is a fundamental consequence of physical symmetries, not an artifact of specific models.
• This work corrects a long-standing assumption in the literature regarding finite size effects.