On the Vacuum Structure of Type II String Compactifications on Calabi-Yau Spaces with H-Fluxes
G. Curio, A. Klemm, D. Luest, S. Theisen
TL;DR
The paper analyzes how internal H-fluxes in Type II string compactifications on Calabi–Yau manifolds lift moduli and typically break N=2 supersymmetry, while aligned fluxes can produce supersymmetric vacua at Calabi–Yau degeneration points. It develops a unified framework in terms of a symplectic, gauged N=2 supergravity description, with a flux-induced superpotential W = ⟨H,Ξ⟩ that can be expressed in terms of period vectors and their duals, and it connects this to the attractor mechanism of N=2 black holes. The authors perform a detailed survey of degeneration points (large volume, conifold, Seiberg–Witten, strong coupling, conformal) in both IIB and IIA pictures, identifying when SUSY vacua can arise and when the scalar potential is minimized, often via attractor-like dynamics. They also show how including NS fluxes can alter the vacuum structure, potentially yielding fully N=2 vacua at finite moduli, and discuss the broader implications for dualities and geometric engineering.
Abstract
We discuss the vacuum structure of type IIA/B Calabi-Yau string compactifications to four dimensions in the presence of n-form H-fluxes. These will lift the vacuum degeneracy in the Calabi-Yau moduli space, and for generic points in the moduli space, N=2 supersymmetry will be broken. However, for certain `aligned' choices of the H-flux vector, supersymmetric ground states are possible at the degeneration points of the Calabi-Yau geometry. We will investigate in detail the H-flux induced superpotential and the corresponding scalar potential at several degeneration points, such as the Calabi-Yau large volume limit, the conifold loci, the Seiberg-Witten points, the strong coupling point and the conformal points. Some emphasis is given to the question whether partial supersymmetry breaking can be realized at those points. We also relate the H-flux induced superpotential to the formalism of gauged N=2 supergravity. Finally we point out the analogies between the Calabi-Yau vacuum structure due to H-fluxes and the attractor formalism of N=2 black holes.
