Any field theory in which this property holds for the Lagrangian, but not for the physical vacuum, must contain * massless bosons by Goldstone's theorem.
Kramers' theorem states that a system must be doubly degenerate if its Hamiltonian has one type of this property. Any field theory in which this property holds for the Lagrangian, but not for the physical vacuum, must contain * massless bosons by Goldstone's theorem. A local gauge's spontaneous loss of this property results in the acquisition of mass by W and Z bosons in the Higgs mechanism. Noether's theorem states that there is a conservation law associated with every continuous one of these. The existence of corresponding bosons and fermions is its hypothetical "super " variety. FTP name this property, invariance under transformations.
Kramers' theorem states that a system must be doubly degenerate if its Hamiltonian has one type of this property.
{Symmetry} (accept {T}-{symmetry} or {Time Reversal Invariance} until *, accept {invariance throughout})