Why does Quantum Field Theory use Lagrangians rather than Hamiltonians?
36380
Why not use the Lagrangian, instead of the Hamiltonian, in nonrelativistic QM?
33669
In what sense is a scalar field observable in QFT?
46053
How to find Hamiltonian from this simple Lagrangian? (tricky)
11358
Eigenvalues of the Lagrangian?
96880
How to obtain Hamiltonian formalism and phase space for Lagrangian with second-derivatives?
38103
A No-Nonsense Introduction to Quantum Field Theory
158717
Why do we prefer "Lagrangian and Hamiltonian mechanics " over the newtonian mechanics?
91314
Advantages of Lagrangian Mechanics over Newtonian Mechanics
94230
I want to understand a trick in the derivation of the Schwinger-Dyson equations
151173
Is the quantum action principle of Schwinger a variational principle?
104320
Why should the Standard Model be renormalizable?
17414
Lagrangian of an effective potential
26125
Does the canonical commutation relation fix the form of the momentum operator?
99312
Why Lagrangian is negative number for a relativistic massive point particle?
88926
Why do we use operators in quantum mechanics?
153656
What Lagrangian counterterms might be needed in a $\phi^ 6$ theory in 3D?
101002
Is there either a Lagrangian or a Hamiltonian formulation of electromagnetism with continuous distributions of magnetic monopoles?