This is more a terminology question. I have seen that some people differentiate between the two types of symmetry: internal symmetry and gauge symmetry (of a field theory).
Is there a difference (in both local and global case), and if there is what is it?
Edit: For example in the case of Dirac equation interacting with electromagnetic field (plus the gauge fixing term) which is invariant under the set of local transformations: ψ→eiθ(x)ψAμ→Aμ+∂μθ(x)
which is internal symmetry (if any) and which is gauge symmetry?
No comments:
Post a Comment