1. High-Energy Physics
- Quantum Electrodynamics (QED): Electron-photon scattering, vacuum polarization, and radiative corrections.
- Quantum Chromodynamics (QCD): Gluon exchange between quarks, hadronization processes, and loop corrections in particle collisions.
- Electroweak Theory: Neutrino interactions, W/Z boson exchange in weak processes.
2. Condensed Matter Physics
- Electron-Electron Interactions: Screening and correlation effects in metals and semiconductors.
- Electron-Phonon Coupling: Superconductivity (BCS theory), phonon-mediated pairing.
- Many-Body Perturbation Theory: GW approximation for quasiparticle energies, Bethe–Salpeter Equation for excitons.
3. Atomic and Molecular Physics
- Photoionization and Scattering: Electron impact ionization, photon absorption/emission processes.
- Correlation Effects in Molecules: Configuration interaction corrections using diagrammatic expansions.
4. Nuclear Physics
- Nucleon-Nucleon Interactions: Meson exchange models represented by diagrams.
- Nuclear Reaction Mechanisms: Perturbative expansions for scattering amplitudes.
5. Quantum Chemistry
- Coupled Cluster Theory: Diagrammatic representation of excitation operators.
- Electron Correlation in Molecules: Perturbative corrections (MP2, MP4) expressed via diagrams.
6. Statistical and Thermal Field Theory
- Finite-Temperature Systems: Matsubara diagrams for thermodynamic properties.
- Phase Transitions: Diagrammatic expansions in critical phenomena.