- #1
taishizhiqiu
- 63
- 4
I recently learned that with (local) gauge invariance, functional quantization needs to factor out volume factor(Faddeev-Popov procedure).
Why does this has to be done?Just to remove infinity? As far as I am concerned, ##\phi^4## theory contains invariance(for example ##\phi\to\phi\cdot e^{i \alpha}##) but do not need such procedure.
What is the difference between the invariance in ##\phi^4## theory and that of Yang-mills theory? I learned that gauge invariance is redundant freedom but what's the exact meaning of redundant freedom?
Why does this has to be done?Just to remove infinity? As far as I am concerned, ##\phi^4## theory contains invariance(for example ##\phi\to\phi\cdot e^{i \alpha}##) but do not need such procedure.
What is the difference between the invariance in ##\phi^4## theory and that of Yang-mills theory? I learned that gauge invariance is redundant freedom but what's the exact meaning of redundant freedom?