What is a Lagrangian of a photon?
34788
Lagrangian for relativistic massless point particle
111611
When can we add a total time derivative of $f(q, \dot{q}, t)$ to a Lagrangian?
35041
What is the difference between Newtonian and Lagrangian mechanics in a nutshell?
57051
Why does Quantum Field Theory use Lagrangians rather than Hamiltonians?
12924
How to derive Maxwell's equations from the electromagnetic Lagrangian?
10953
Elementary argument for conservation laws from symmetries *without* using the Lagrangian formalism
99789
Beyond Hamiltonian and Lagrangian mechanics
131016
Question about Klein-Gordon field Lagrangian
120474
Does the lagrangian contain all the information about the representations of the fields in QFT?
15019
Does a single photon's energy depend on frequency? (photoelectric effect)
134172
Photons acting as carriers of both attractive and repulsive forces
17414
Lagrangian of an effective potential
138908
Most general Lagrangian in CFT in 0+1D
153727
Constant term in Lagrangian
96880
How to obtain Hamiltonian formalism and phase space for Lagrangian with second-derivatives?
18054
Is there a proof from the first principle that the Lagrangian L = T - V?
129289
What is the origin of the factor of $-1/4$ in the Maxwell Lagrangian?