Classifying Isolated Symplectic Singularities via 3d $\mathcal{N}=4$ Coulomb Branches
Antoine Bourget, Quentin Lamouret, Sinan Moura Soysüren, Marcus Sperling
TL;DR
The paper addresses the problem of classifying unitary quivers whose $3d \mathcal{N}=4$ Coulomb branches are isolated conical symplectic singularities (ICSSs). It adopts the Decay and Fission conjecture to translate the Coulomb-branch stratification into a combinatorial poset of quiver fission/decay products, enabling a complete classification under this hypothesis. The authors identify three new stable quiver families, with $gb_n$ and $gd_n$ yielding two new ICSS families and $gc_n$ providing a novel realization of a known family $\overline{h}_{n,\sigma}$; they also recover all previously known ICSSs (except certain $D$ and $E$ types) within a uniform framework and compute HWGs/Hilbert series to support the geometry identifications. Additionally, the work extends the framework to generalized $(p,q)$-edges, broadening the scope of stable unitary quivers realizing ICSSs and suggesting avenues to prove the conjecture directly from Coulomb-branch data. Overall, the results offer a uniform, physics-inspired route to cataloging ICSSs arising as $3d$ $\mathcal{N}=4$ Coulomb branches, with potential implications for Higgs-branch physics and geometric representation theory.
Abstract
Based on the Decay and Fission Conjecture, we provide a classification of unitary quivers whose 3d $\mathcal{N}=4$ Coulomb branches exhibit isolated singularities. This yields the complete list of isolated conical symplectic singularities that can arise in this way. In the process, we identify three new families of stable quivers: two giving rise to previously unknown isolated symplectic singularities, and one offering a novel realization of a known family.
