Network, cluster coordinates and N = 2 theory II: Irregular singularity
Dan Xie
TL;DR
This work develops a geometric framework to construct cluster coordinates and BPS quivers for a broad class of Argyres-Douglas and asymptotically free N=2 theories by using Stokes data from irregular singularities on bordered Riemann surfaces. By translating irregular singularity data into dot diagrams, bipartite networks, and triangulation-based quivers, the authors connect the Coulomb-branch geometry to Grassmannian cells and propose that the network quiver is the BPS quiver. The method covers Type I–IV AD theories and linear/quiver gauge theories with AD matter, providing explicit examples where quiver mutations and Grassmannian cell structures align with known spectra and dualities. The approach promises practical tools for computing BPS spectra, wall-crossing, and line-operator data, and suggests deep links to spectral networks and Y-systems across N=2 theories.
Abstract
Cluster coordinates for a large class of Argyres-Douglas and asymptotical free theories are constructed using network on bordered Riemann surface. Such N = 2 theories are engineered using six dimensional (2, 0) theory on Riemann surface with irregular and regular singularities. The Stokes phenomenon plays an important role in our construction. Our results are expected to be very useful in studying BPS spectrum, wall crossing, and line operators of these theories, etc. In particular, we conjecture that the quiver from the network is the BPS quiver. Moreover, our construction provides a simple way to build the minimal network for cells of positive Grassmannia .
