A Rigorous Derivation of Electromagnetic Self-force

May, 2009
52 pages
Published in:
  • Phys.Rev.D 80 (2009) 024031
e-Print:

Citations per year

20092013201720212025024681012
Abstract: (arXiv)
During the past century, there has been considerable discussion and analysis of the motion of a point charge, taking into account 'self-force' effects due to the particle's own electromagnetic field. We analyze the issue of 'particle motion' in classical electromagnetism in a rigorous and systematic way by considering a one-parameter family of solutions to the coupled Maxwell and matter equations corresponding to having a body whose charge-current density Ja(λ)J^a(\lambda) and stress-energy tensor Tab(λ)T_{ab} (\lambda) scale to zero size in an asymptotically self-similar manner about a worldline γ\gamma as λ0\lambda \to 0. In this limit, the charge, qq, and total mass, mm, of the body go to zero, and q/mq/m goes to a well defined limit. The Maxwell field Fab(λ)F_{ab}(\lambda) is assumed to be the retarded solution associated with Ja(λ)J^a(\lambda) plus a homogeneous solution (the 'external field') that varies smoothly with λ\lambda. We prove that the worldline γ\gamma must be a solution to the Lorentz force equations of motion in the external field Fab(λ=0)F_{ab}(\lambda=0). We then obtain self-force, dipole forces, and spin force as first order perturbative corrections to the center of mass motion of the body. We believe that this is the first rigorous derivation of the complete first order correction to Lorentz force motion. We also address the issue of obtaining a self-consistent perturbative equation of motion associated with our perturbative result, and argue that the self-force equations of motion that have previously been written down in conjunction with the 'reduction of order' procedure should provide accurate equations of motion for a sufficiently small charged body with negligible dipole moments and spin. (There is no corresponding justification for the non-reduced-order equations.)
  • 04.25.Nx
  • 04.30.Db
  • 04.40.Nr
  • force: Lorentz
  • spin: force
  • tensor: energy-momentum
  • field equations
  • electromagnetic field: self-force
  • electromagnetic field: external field
  • electromagnetic field: classical