This question already has an answer here:

In sense of classical mechanics+special relativity what is lagrangian of a photon? Lagrangian of a relativistic massive particle is as follows: $$ L_{massive}= -mc\sqrt{c^2-v^2} $$ So is it a zero?


marked as duplicate by ACuriousMind, Sebastian Riese, John Rennie, Bill N, HDE 226868 Oct 12 '15 at 23:02

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


Classical electrodynamics has a lagrangian for the classical fields, see discussion here .

The photon is an elementary particle and does not have a classical existence.

Here is on page 5 the Lagrangian for a photon

photon langrangian


Not the answer you're looking for? Browse other questions tagged or ask your own question.