Why is the Lagrangian approach preferred over the Hamiltonian approach in QFT?
57051
Why does Quantum Field Theory use Lagrangians rather than Hamiltonians?
153727
Constant term in Lagrangian
4989
Why are there only derivatives to the first order in the Lagrangian?
4421
Proof that total derivative is the only function that can be added to Lagrangian without changing the EOM
40355
Equivalence between Hamiltonian and Lagrangian Mechanics
48068
Any good resources for Lagrangian and Hamiltonian Dynamics?
30992
How do you determine the Lagrangian?
131016
Question about Klein-Gordon field Lagrangian
90325
Why use the derivative and not the symmetric derivative?
153656
What Lagrangian counterterms might be needed in a $\phi^ 6$ theory in 3D?
147524
Why is the "canonical momentum" for the Dirac equation not defined in terms of the "gauge covariant derivative"?
138424
Scalar field Derivative. Real vs Complex
41407
How to derive or justify the expressions of momentum operator and energy operator?
158717
Why do we prefer "Lagrangian and Hamiltonian mechanics " over the newtonian mechanics?
87914
Contradictory result for scalar-field propagator from Feynman rules and LSZ formula
72898
Is "quantizing" a field different from "quantizing" a particle?
17120
Why use Fourier expansion in Quantum Field Theory?