Kahler Potentials of Chiral Matter Fields for Calabi-Yau String Compactifications

TL;DR

This paper develops a perturbative method to determine the modular dependence of the Kahler potential for matter fields in Calabi-Yau string compactifications, aiding in understanding supersymmetry breaking and matter normalization.

Contribution

It introduces a novel perturbative approach to extract the modular weights of matter fields in complex Calabi-Yau compactifications, extending beyond simple models.

Findings

Computed modular weights for bifundamental matter on D7 branes.

Applied techniques to large-volume IIB flux compactifications.

Results consistent with known toroidal compactification data.

Abstract

The Kahler potential is the least understood part of effective N=1 supersymmetric theories derived from string compactifications. Even at tree-level, the Kahler potential for the physical matter fields, as a function of the moduli fields, is unknown for generic Calabi-Yau compactifications and has only been computed for simple toroidal orientifolds. In this paper we describe how the modular dependence of matter metrics may be extracted in a perturbative expansion in the Kahler moduli. Scaling arguments, locality and knowledge of the structure of the physical Yukawa couplings are sufficient to find the relevant Kahler potential. Using these techniques we compute the `modular weights' for bifundamental matter on wrapped D7 branes for large-volume IIB Calabi-Yau flux compactifications. We also apply our techniques to the case of toroidal compactifications, obtaining results consistent with those present in the literature. Our techniques do not provide the complex structure moduli dependence of the Kahler potential, but are sufficient to extract relevant information about the canonically normalised matter fields and the soft supersymmetry breaking terms in gravity mediated scenarios.