  Supersymmetric nonlinear sigma models are obtained from linear sigma models
by imposing supersymmetric constraints. If we introduce auxiliary chiral and
vector superfields, these constraints can be expressed by D-terms and F-terms
depending on the target manifolds. Auxiliary vector superfields appear as gauge
fields without kinetic terms. If there are no D-term constraints, the target
manifolds are always non-compact manifolds. When all the degrees of freedom in
these non-compact directions are eliminated by gauge symmetries, the target
manifold becomes compact. All supersymmetric nonlinear sigma models, whose
target manifolds are the hermitian symmetric spaces, are successfully
formulated as gauge theories.
