Duality Walls, Duality Trees and Fractional Branes
Sebastian Franco, Amihay Hanany, Yang-Hui He, Pavlos Kazakopoulos
TL;DR
The paper develops a framework to study non-conformal quiver gauge theories from D-brane probes on toric singularities by combining NSVZ beta functions with $a$-maximization to determine exact anomalous dimensions. It uses duality trees and Picard-Lefschetz monodromies to analyze cascades, uncovering Duality Walls—finite-energy scales where Seiberg duality halts and the degrees of freedom proliferate—along with a Z2 symmetry that mirrors T-duality in the holographic dual. The analysis applied to the conifold, $F_0$, and $dP_1$ reveals closed cycles, toric islands, and wall-structured RG flows, with implications for horizon volumes via the AdS/CFT correspondence. The work culminates in a general methodology for toric and del Pezzo geometries and provides horizon-volume results for several examples, connecting field-theoretic data to geometric invariants.
Abstract
We compute the NSVZ beta functions for N = 1 four-dimensional quiver theories arising from D-brane probes on singularities, complete with anomalous dimensions, for a large set of phases in the corresponding duality tree. While these beta functions are zero for D-brane probes, they are non-zero in the presence of fractional branes. As a result there is a non-trivial RG behavior. We apply this running of gauge couplings to some toric singularities such as the cones over Hirzebruch and del Pezzo surfaces. We observe the emergence in string theory, of ``Duality Walls,'' a finite energy scale at which the number of degrees of freedom becomes infinite, and beyond which Seiberg duality does not proceed. We also identify certain quiver symmetries as T-duality-like actions in the dual holographic theory.
