Partial breaking of global D=4 supersymmetry, constrained superfields, and3-brane actions - art. no. 106001

We show that the connection between partial breaking of supersymmetry and n onlinear actions is not accidental and has to do with constraints that lead directly to nonlinear actions of the Born-Infeld type. We develop a constr ained superfield approach that gives a universal way of deriving and using these actions. In particular, we find the manifestly supersymmetric form of the action of the 3-brane in 6-dimensional space in terms of N = 1 superfi elds by using the tensor multiplet as a tool. We explain the relation betwe en the Born-Infeld action and the model of partial N = 2 supersymmetry brea king by a dual D term. We represent the Born-Infeld action in a novel form quadratic in the gauge field strengths by introducing two auxiliary complex scalar fields; this makes duality covariance and the connection with the N = 1 supersymmetric extension of the action very transparent. We also sugge st a general procedure for deriving manifestly duality symmetric actions, e xplaining in a systematic way relations between previously discussed Lorent z-covariant and noncovariant actions. [S0556-2821(99)05508-3].