String Theory Realizations of the Nilpotent Goldstino

TL;DR

This paper demonstrates how the spectrum of an anti-D3-brane in string theory models matches a nilpotent superfield with a goldstino, supporting the use of such superfields in describing non-linear supersymmetry breaking.

Contribution

It explicitly shows the correspondence between anti-D3-brane spectra and nilpotent superfields in string models, providing evidence for their role in non-linear supersymmetry.

Findings

Spectrum of anti-D3-brane matches nilpotent superfield content

Supports use of nilpotent superfields in string theory supersymmetry breaking

Implications for de Sitter vacua and cosmology

Abstract

We describe in detail how the spectrum of a single anti-D3-brane in four-dimensional orientifolded IIB string models reproduces precisely the field content of a nilpotent chiral superfield with the only physical component corresponding to the fermionic goldstino. In particular we explicitly consider a single anti-D3-brane on top of an O3-plane in warped throats, induced by $(2,1)$ fluxes. More general systems including several anti-branes and other orientifold planes are also discussed. This provides further evidence to the claim that non-linearly realized supersymmetry due to the presence of antibranes in string theory can be described by supersymmetric theories including nilpotent superfields. Implications to the KKLT and related scenarios of de Sitter moduli stabilization, to cosmology and to the structure of soft SUSY-breaking terms are briefly discussed.