Equations of motion for N=4 supergravity with antisymmetric tensor from its geometric description in central charge superspace

TL;DR

This paper derives the equations of motion for N=4 supergravity with an antisymmetric tensor from its geometric superspace formulation, confirming their consistency with previous Lagrangian-based results.

Contribution

It provides a geometric derivation of the equations of motion for N=4 supergravity with antisymmetric tensor directly from superspace constraints, without relying on a Lagrangian.

Findings

Equations of motion match those from Nicolai and Townsend's Lagrangian formulation.

Superspace geometry fully determines the on-shell supergravity dynamics.

The approach confirms the consistency of geometric and Lagrangian methods.

Abstract

We consider the geometrical formulation in central charge superspace of the N=4 supergravity containing an antisymmetric tensor gauge field. The theory is on-shell, so clearly, the constraints used for the identification of the multiplet together with the superspace Bianchi identities imply equations of motion for the component fields. We deduce these equations of motion in terms of supercovariant quantities and then, we give them in terms of component fields. These equations of motion, deduced from the geometry, without supposing the existence of a Lagrangian, are found to be the same as those derived from the Lagrangian given in the component formulation of this N=4 supergravity multiplet by Nicolai and Townsend.