Realistic D-Brane Models on Warped Throats: Fluxes, Hierarchies and Moduli Stabilization

TL;DR

This paper constructs string theory models with warped throats that realize the hierarchy problem, stabilize moduli, and produce Standard Model-like spectra, offering a concrete embedding of Randall-Sundrum scenarios.

Contribution

It presents explicit string theory constructions with warped geometries, chiral spectra, and moduli stabilization, advancing realistic model building within string theory frameworks.

Findings

Models with Standard Model gauge group and three fermion families

Moduli stabilized by fluxes and non-perturbative effects

Potential for full moduli stabilization and de Sitter vacua

Abstract

We describe the construction of string theory models with semirealistic spectrum in a sector of (anti) D3-branes located at an orbifold singularity at the bottom of a highly warped throat geometry, which is a generalisation of the Klebanov-Strassler deformed conifold. These models realise the Randall-Sundrum proposal to naturally generate the Planck/electroweak hierarchy in a concrete string theory embedding, and yielding interesting chiral open string spectra. We describe examples with Standard Model gauge group (or left-right symmetric extensions) and three families of SM fermions, with correct quantum numbers including hypercharge. The dilaton and complex structure moduli of the geometry are stabilised by the 3-form fluxes required to build the throat. We describe diverse issues concerning the stabilisation of geometric Kahler moduli, like blow-up modes of the orbifold singularities, via D term potentials and gauge theory non-perturbative effects, like gaugino condensation. This local geometry, once embedded in a full compactification, could give rise to models with all moduli stabilised, and with the potential to lead to de Sitter vacua. Issues of gauge unification, proton stability, supersymmetry breaking and Yukawa couplings are also discussed.