# Symmetry, groups and gauge theories in the standard model

marlon said:
Willem,

It is useless to use field equations because the symmetries at hand (which are broken and thus yield mass) are inherent to the Lagrangian, not to the field equation !!!
The symmetries like U(1):

$$\Phi \rightarrow \Phi e^{i \phi}$$

apply to the fields right?

Again i suggest you look at the examples i gave in the two references...

regards
marlon
I did! But the potential I used can be shown to be the most general form that can be used in a renormalizable theory (according to my book). So it can't harm to use that one...

ps : when using the variational principle, you can vary to both fields. The two approaches are equivalent. This does NOT mean that you can mix them up.
Where did I mix these up?