RENORMALIZABILITY OF A (2+1)-DIMENSIONAL SUPERSYMMETRIC NONLINEAR SIGMA-MODEL IN SUPERSPACE

The superspace formulation of an O(N)-invariant supersymmetric nonlinear sigma-model is presented. The renormalizability of this model, explicitly carried out up to next-to-leading order in 1/N using component fields in an earlier paper, is proven to all orders in the 1/N expansion by appealing to parity, time-reversal, and supersymmetry invariances. Furthermore, it is proven that the Lagrange multiplier superfield, which imposes the nonlinear constraint, does not get renormalized in any order in 1/N.