$U(1)$ local gauge invariance in QED
68831
Why mass terms are forbidden?
68267
$SU(3)$ irreducible representations with tensor method
120474
Does the lagrangian contain all the information about the representations of the fields in QFT?
77761
Arrow and flow of charge in fermion propagator
45061
Physical interpretation of $Q^i = \partial _\nu T^{i \nu}$
61603
Why is the Yang–Mills existence and mass gap problem so fundamental?
116427
$(c^{\mu}\partial_{\mu}-m)\phi(x)=0$ not Lorentz-invariant?
152528
Bound states in QED
141907
Haag's theorem and practical QFT computations
69389
Gauge fields and strings: Loop equations
51122
Lagrangian of Schrodinger field
147597
QED symbol in a custom theorem environment
130422
Derivation of the Noether current
107532
What is a gauge in a gauge theory?
15275
How do you go from quantum electrodynamics to Maxwell's equations?
28416
Show that $\partial_\nu T^{\mu\nu} = - j_\nu F^{\mu\nu}$
106506
How to derive completeness relation in quantum field theory with a Lorentz invariant measure?