QED lagrangian: gauge fixing term
44239
Why the extra term $\frac{1}{2}(\partial_{\rho}A^{\rho})^2$ in the photon Lagrangian?
36152
Bessel function representation of spacelike KG propagator
11358
Eigenvalues of the Lagrangian?
27296
Derivation of Lagrangian of electromagnetic field from Lorentz force
79094
Perturbation expansion with path integrals
104604
How do I find the values for the structure constants ($f^{abc}$) of a gauge group?
150081
Deriving Lagrangian density for electromagnetic field
147524
Why is the "canonical momentum" for the Dirac equation not defined in terms of the "gauge covariant derivative"?
122263
Geometry of Yang-Mills theory
18414
Energy-Momentum Tensor in QFT vs. GR
11181
Counting degrees of freedom of gauge bosons
113610
Spinor field normalisation from poles in the propagator
99789
Beyond Hamiltonian and Lagrangian mechanics
149741
Review: If true, what makes the vacuum of a local ${\rm U(1)}$ gauge theory unique?
154772
The Momentum Operator in QM
114901
In what sense is the proper/effective action $\Gamma[\phi_c]$ a quantum-corrected classical action $S[\phi]$?
98358
A variational problem with a lagrangian , what is the lagrangian?