  The fixed points of a natural torus action on the Hilbert schemes of points
in C^2 are quiver varieties of infinite type A. The equivariant cohomology of
the Hilbert schemes and quiver varieties can be given the structure of bosonic
and fermionic Fock spaces respectively. Then the localization theorem, which
relates the equivariant cohomology of a space with that of its fixed point set,
yields a geometric realization of the important boson-fermion correspondence.
