The gauge-symmetry tag has no wiki summary.
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Some questions about Ward-Takahashi Identity
I'm a learner of Peskin and Schroeder's textbook of quantum field theory.
I have proceeded to Ward-Takahashi identity and have one question when I look for Wikipedia for reference.
The following is ...
4
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1answer
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Noether's identities
I have some questions about the Noether's second theorem (generally not covered by field theory books):
What is the most general Noether identity for (classical) field theories?
Why are Noether ...
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0answers
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CP-symmetry and Ward identities and finite temperature
I have a few questions about Ward-identities which I summarize here. For each I am very greateful for answers and references to literature.
Wikipedia states about Ward-identities:
The ...
4
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3answers
355 views
Noether theorem, gauge symmetry and conservation of charge
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
...
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What does it mean to gauge a group?
I'm starting to learn about gauge theories and Goldstone bosons. What does it mean for a group to be gauged?
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2answers
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Why is the Yang-Mills gauge group assumed compact and semi-simple?
What is the motivation for including the compactness and semi-simplicity assumptions on the groups that one gauges to obtain Yang-Mills theories? I'd think that these hypotheses lead to physically ...
5
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1answer
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Coulomb gauge fixing and “normalizability”
The Setup
Let Greek indices be summed over $0,1,\dots, d$ and Latin indices over $1,2,\dots, d$. Consider a vector potential $A_\mu$ on $\mathbb R^{d,1}$ defined to gauge transform as
$$
A_\mu\to ...
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1answer
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Introduction to Gauge Symmetries: Good, Bad or Ugly?
I'm trying to come up with a good (as in intuitive and not 'too wrong') definition of a gauge symmetry.
This is what I have right now:
A dynamical symmetry is a (differentiable) group of ...
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2answers
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Gauge invariant scalar potentials
If $\Phi$ is a multi-component scalar field which is transforming in some representation of a gauge group say $G$ then how general a proof can one give to argue that the potential can only be a ...
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1answer
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What is a “free” non-Abelian Yang-Mill's theory?
I hope this question will not be closed down as something completely trivial!
I did not think about this question till in recent past I came across papers which seemed to write down pretty much ...
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1answer
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Why does charge conservation due to gauge symmetry only hold on-shell?
While deriving Noether's theorem or the generator(and hence conserved current) for a continuous symmetry, we work modulo the assumption that the field equations hold. Considering the case of gauge ...
