A New Mechanism of Kahler Moduli Stabilization in Type IIB Theory

TL;DR

This work introduces a perturbative, leading-order mechanism for complete moduli stabilization in Type IIB Calabi–Yau orientifolds. By combining ISD three-form fluxes to fix the dilaton and complex-structure moduli with flux-induced masses on magnetized D-branes and Fayet-Iliopoulos terms to lift Kahler-moduli flat directions, the authors claim a general stabilization mechanism that does not rely on non-perturbative superpotentials. The ISD case yields positive mass terms and a global minimum at vanishing vacuum energy, with Kahler moduli fixed at their SUSY values in a manner tied to the open-string sector; IASD fluxes are discussed as alternative, less favorable possibilities. A concrete toroidal example on $T6/(Z2\times Z2\times \Omega R)$ demonstrates the procedure, though the resulting soft terms are large, marking the model as a toy realization rather than a fully realistic compactification. Overall, the paper proposes a generic, perturbative route to stabilize all closed-string moduli, with potential extensions to warped geometries and de Sitter vacua, but highlights challenges in achieving phenomenologically viable scales in simple setups.

Abstract

We study the scalar potential in supersymmetric (orientifolded) Calabi Yau compactifications of Type IIB theory. We present a new mechanism to stabilize all closed string moduli at leading order in α^{'} by introducing consistently fluxes. As usual we consider the dilaton and the complex structure moduli stabilized by turning on three-form fluxes that couple to the F-part of the scalar potential. Kahler moduli get fixed by the combined action of the flux-induced scalar masses with magnetic fields of the open string sector, and Fayet-Illiopoulos terms. For supersymmetric three-form fluxes the model is N=1, otherwise the mass terms are the scalar soft breaking terms of the SM fields. For the case of imaginary self dual three-form fluxes (ISD), the mass terms are positive and the minimum at the potential is at exactly zero energy. We argue that, under generic assumptions, this is a general mechanism for the full stabilization of closed string moduli. The vacua depend explicitly on the fluxes introduced in the manifold. A concrete realization of this mechanism on type IIB on a (T^ {6}/Z_{2}xZ_{2}) orientifold is provided.