Duality Cascades and Affine Weyl Groups

TL;DR

This paper uncovers a hidden affine Weyl group structure in duality cascades of brane configurations, revealing their finiteness and unique endpoints through geometric and algebraic analysis.

Contribution

It demonstrates that duality cascades correspond to affine Weyl group translations, providing a new algebraic framework for understanding their structure and endpoints.

Findings

Duality cascades are characterized by affine Weyl chambers.

The affine Weyl group ensures the finiteness and uniqueness of cascade endpoints.

The framework extends to cases with Fayet-Iliopoulos parameters.

Abstract

Brane configurations in a circle allow subsequent applications of the Hanany-Witten transitions, which are known as duality cascades. By studying the process of duality cascades corresponding to quantum curves with symmetries of Weyl groups, we find a hidden structure of affine Weyl groups. Namely, the fundamental domain of duality cascades consisting of all the final destinations is characterized by the affine Weyl chamber and the duality cascades are realized as translations of the affine Weyl group, where the overall rank in the brane configuration associates to the grading operator of the affine algebra. The structure of the affine Weyl group guarantees the finiteness of the processes and the uniqueness of the endpoint of the duality cascades. In addition to the original duality cascades, we can generalize to the cases with Fayet-Iliopoulos parameters. There we can utilize the Weyl group to analyze the fundamental domain similarly and find that the fundamental domain continues to be the affine Weyl chamber. We further interpret the Weyl group we impose as a "half" of the Hanany-Witten transition.