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### Gauge symmetry is not a symmetry?

I have read before in one of Seiberg's articles something like, that gauge symmetry is not a symmetry but a redundancy in our description, by introducing fake degrees of freedom to facilitate ...
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### Is the converse of Noether's first theorem true: Every conservation law has a symmetry?

Noether's (first) theorem states that any differentiable symmetry of the action of a physical system has a corresponding conservation law. Is the converse true: Any conservation law of a physical ...
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### Noether charge of local symmetries

If our Lagrangian is invariant under a local symmetry, then, by simply restricting our local symmetry to the case in which the transformation is constant over space-time, we obtain a global symmetry, ...
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### Noether's theorem and gauge symmetry

I'm confused about Noether's theorem applied to gauge symmetry. Say we have $$\mathcal L=-\frac14F_{ab}F^{ab}.$$ Then it's invariant under $A_a\rightarrow A_a+\partial_a\Lambda.$ But can I say that ...
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I'm trying to understand Noether's theorem, and it's application to gauge symmetry. Below what I've done so far. First, the global gauge symmetry. I'm starting with the Lagragian $$L_{1}=\partial^{\... 3answers 3k views ### What is the symmetry which is responsible for preservation/conservation of electrical charges? Another Noether's theorem question, this time about electrical charge. According to Noether's theorem, all conservation laws originate from invariance of a system to shifts in a certain space. For ... 2answers 3k views ### Physical difference between gauge symmetries and global symmetries There are plenty of well-answered questions on Physics SE about the mathematical differences between gauge symmetries and global symmetries, such as this question. However I would like to understand ... 1answer 4k views ### Noether's first theorem and classical proof of electric charge conservation How to prove conservation of electric charge using Noether's first theorem according to classical (non-quantum) mechanics? I know the proof based on using Klein–Gordon field, but that derivation use ... 0answers 432 views ### From gauge invariance to charge conservation in covariant electrodynamics I tried to solve the equations of motion using the action for the electromagnetic field interacting with a current, like$$ L = F_{\mu\nu}F^{\mu\nu} + A_{\nu}j^{\nu} $$getting the right Maxwell's ... 0answers 197 views ### Noether Charge and Gauge Fields I understand the global gauge symmetry results conserved charges associated with the symmetry. My question is, why don't we have conserved charges associated with local gauge symmetry of the gauge ... 0answers 161 views ### Applying Noether's Theorem to local invariance I have realised that I am unsure about how I can apply Noether's theorem to a Lagrangian with local invariance. For instance, the following Lagrangian has a local U(1) invariance:$$\mathcal{L}=(D_{...
We know that there are two ways to get charge conservation in electrodynamics by using the following action: $$S[A]~=~\int\! d^4x {\cal L},$$  {\cal L} ~=~{\cal L}_{\rm Maxwell} + {\cal L}_{\rm ...