Goldstone boson: Difference between revisions

→‎Goldstone's Argument: not in every gauge (see talk)
(→‎Goldstone's Argument: not in every gauge (see talk))
Letting A become large leads to a contradiction.
This argument fails completely for a gauge theory since the space of states for a gauge theory now has a [[positive semidefinite]] [[norm]] instead of a positive definite one, and it's not possible to construct an orthogonal state using the previous construction.
== Nonrelativistic theories ==