1203.0609 (Haruki Watanabe et al.)

Number of Nambu-Goldstone bosons and partially symplectic geometry of
coset space    [PDF]

Haruki Watanabe, Hitoshi Murayama

Using the non-relativistic effective Lagrangian formalism, we prove that the number of Nambu-Goldstone bosons is always equal to the number of broken generators minus the number of pairs of generators whose commutator have a nonzero expectation value. It turns out that Nambu-Goldstone bosons of the latter category live on the symplectic base of the coset space.

View original: http://arxiv.org/abs/1203.0609