| | Gauge Symmetry Breaking and Boundary Conditions for Gauge Transformation (Site not responding. Last check: 2007-10-08) |
 | | In gauge symmetry breaking, on the other hand, the resulting set is Gglobal/Hglobal and not Ggauge/Hgauge (where the "global" and "gauge" indices indicate the groups of global and gauge transformations respectively) as "naively" expected. |
 | | Moreover, gauge transformations leave physical states invariant (in other words, states related by a gauge transformation are considered equivalent), and the vacuums are definitely physical states (and inequivalent ones, I guess, otherwise the division to sectors would be meaningless in the physical state space). |
 | | Therefore, the gauge transformations may be classified by their limit in the infinity into a Gglobal group. |
| www.lns.cornell.edu /spr/2000-03/msg0022791.html (335 words) |