How do electrons couple to gauge field?

[Polyrhythmic]

Furthermore, I don't see how the Ward-Takahashi identities have any impact on the form of the original QED Lagrangian.

 

[Dickfore]

Furthermore, I don't see how the Ward-Takahashi identities have any impact on the form of the original QED Lagrangian.

You should familiarize yourself with renormalization.

 

[Polyrhythmic]

You should familiarize yourself with renormalization.

I'm familiar with renormalization, that's why I wrote "original" instead of "renormalized" Lagrangian.

 

[Dickfore]

I'm familiar with renormalization, that's why I wrote "original" instead of "renormalized" Lagrangian.

If you really understood the gist of Renormalization, you would know that the "original" Lagrangian is not connected to reality.

 

[Polyrhythmic]

I understand that. Apparently we were both confused with what the other one meant! ;)

 

[Dickfore]

I understand that. Apparently we were both confused with what the other one meant! ;)

Actually, my comments started as a reply to OP's https://www.physicsforums.com/showpost.php?p=3491614&postcount=25" where he mentions "Proca Lagrangian". I don't know what your intention was or whatever it was that you had in mind.

 

[Polyrhythmic]

Actually, my comments started as a reply to OP's https://www.physicsforums.com/showpost.php?p=3491614&postcount=25" where he mentions "Proca Lagrangian". I don't know what your intention was or whatever it was that you had in mind.

I see, now everything is clear to me, I didn't realize you were talking about Proca theory. Sorry for the confusion!