Superspace formulation of new non-linear sigma models

Abstract

The superspace formulation of two classes of supersymmetric non-linear σ-models are presented. Two alternative N = 1 superspace formulations are given for the d = 2 supersymmetric non-linear σ-models with Killing vector potentials: (a) formulation uses an active central charge and, (b) formulation uses a spurion superfield without inducing a classical breakdown of supersymmetry. The N = 2 vector multiplet is used to construct a new class of d = 4 non-linear σ-models which when reduced to d = 2 possess N = 4 supersymmetry. Implications of these two classes of non-linear σ-models for N 4 superfield supergravity are discussed.