A goldstino at the bottom of the cascade

TL;DR

This paper investigates supersymmetry breaking solutions in a five-dimensional supergravity model related to the Klebanov-Strassler background, identifying conditions under which a goldstino mode appears in the dual field theory.

Contribution

It demonstrates that solutions associated with antiD-branes at the conifold tip correspond to vacua with a goldstino, providing a necessary check for supersymmetry breaking in the cascading gauge theory.

Findings

Goldstino mode presence in specific solutions

Ward identities hold in supersymmetry breaking vacua

Independence from IR singularity resolution

Abstract

Working within a five-dimensional consistent truncation of type IIB supergravity dimensionally reduced on $T^{1,1}$, we consider supersymmetry breaking solutions with the asymptotics of the supersymmetric Klebanov-Strassler background. There exists a two-parameter family of such solutions. Within this family, we show that those (and only those) solutions related to antiD-branes at the tip of the conifold correspond to dual field theory vacua where a goldstino mode is present and supercurrent Ward identities hold. Our findings do not depend on the IR singularity of the dual backgrounds, nor on its resolution. As such, they constitute an independent, necessary check for the existence of supersymmetry breaking vacua in the conifold cascading gauge theory. Our analysis relies on a holographic derivation of the Ward identities which has a wider applicability, beyond the specific system and symmetries considered here.