Higher-Order Processes

The following sections are included:

• Example–Scattering in External Field

  • Feynman Diagrams

  • First-Order

  • Vertex Insertion

  • Vacuum Polarization

  • Self-Energy Insertions

• Ward's Identity

• Electron Self-Energy

  • General Form

  • Evaluation

  • Mass Renormalization

• Vertex

  • General Form

  • Ward's Identity

  • Evaluation

  • The Constant L

  • The Infrared Problem

  • Schwinger Moment

• External Lines and Wavefunction Renormalization

  • Cancellation of Divergences

• Vacuum Polarization

  • Evaluation

  • General Form

  • Limiting Cases

  • Insertion

  • Charge Renormalization

  • Charge Strength

• Renormalization Theory

  • Proper Self-Energies

  • Proper Vertex

  • Ward's Identity

  • Ward's Vertex Construct

  • Finite Parts

  • Proof of Renormalization

  • The Renormalization Group