N=3 Warped Compactifications

TL;DR

The paper constructs and analyzes warped Type IIB compactifications on $T^6/{\\bf Z}_2$ with three-form flux that preserve $D=4$, ${\\cal N}=3$ supersymmetry. It derives the orientifold projection, flux quantization subtleties, Bianchi identities, and a simple flux class leading to a $(0,3)$-type $G_{(3)}$ background, then computes the low-energy spectrum and shows the moduli space forms a coset $U(3,3+N)/U(3)\times U(3+N)$ consistent with ${\\cal N}=3$ supergravity. The work further investigates dualities, showing that flux and finite coupling nontrivially break the ${\\cal N}=4$ duality structure to a restricted ${\\cal N}=3$ regime, with some dualities ending up as bound-state or discrete shift symmetries, and discusses the need for future analysis of the full duality group. Overall, this framework provides a controlled arena to study warped compactifications with ${\\cal N}=3$ SUSY, moduli stabilization, and nonperturbative dualities.

Abstract

Orientifolds with three-form flux provide some of the simplest string examples of warped compactification. In this paper we show that some models of this type have the unusual feature of D=4, N=3 spacetime supersymmetry. We discuss their construction and low energy physics. Although the local form of the moduli space is fully determined by supersymmetry, to find its global form requires a careful study of the BPS spectrum.