It is possible, however, to modify the action, such that the regular methods will be applicable by adding some additional fields, which break the gauge symmetry, which are called the "ghost fields".
This often requires adding some additional fields, which are called the "ghost fields". It is possible, however, to modify the action such that the regular methods will be applicable.
It is possible, however, to modify the action such that the regular methods will be applicable. This often requires adding some additional fields, which are called the "ghost fields".
It is possible, however, to modify the action such that the regular methods will be applicable. This often requires adding some additional fields, which are called the "ghost fields".