Lorentz invariance of Action or Lagrangian?
61070
Lorentz invariance of the integration measure
87259
Constraints of relativistic point particle in Hamiltonian mechanics
158717
Why do we prefer "Lagrangian and Hamiltonian mechanics " over the newtonian mechanics?
114672
Why do we use the Lagrangian and Hamiltonian instead of other related functions?
70880
Invariance of canonical Hamiltonian equation when adding the total time derivative of a function of $q_i$ and $t$ to the Lagrangian
10785
Form of the Classical EM Lagrangian
17451
Expanding electromagnetic field Lagrangian in terms of gauge field
112209
Landau's argument for dependence of Lagrangian on magnitude of velocity
78924
What is $c$ in the Lorentz force expression?
72721
Do an action and its Euler-Lagrange equations have the same symmetries?
140184
Why all theories are Lorentz invariant?
67641
Why should field operators satisfy the classical equations of motion?
114901
In what sense is the proper/effective action $\Gamma[\phi_c]$ a quantum-corrected classical action $S[\phi]$?
68813
Geodesic Equation from variation: Is the squared lagrangian equivalent?
83175
Infinitesimal transformations for a relativistic particle
55540
Electric charge is lorentz invariant
152446
Noether's Theorem and scale invariance