Vacua, Symmetries, and Higgsing of Chern-Simons Matter Theories
Fabio Marino, Marcus Sperling
TL;DR
The paper develops a comprehensive framework to analyze vacua and RG flows of 3d Chern–Simons matter theories with $\mathcal{N}=3$ or enhanced $\mathcal{N}=4$ supersymmetry using Type IIB brane constructions and magnetic quivers. For $|\kappa|=1$ it employs explicit $SL(2,\mathbb{Z})$ dualities to map CS theories to Lagrangian $\mathcal{N}=4$ quivers, enabling complete Higgs and Coulomb branch descriptions via quiver methods and index/Hilbert-space checks. For $|\kappa|>1$ the authors introduce two magnetic quivers, $\mathsf{MQ}_{\text{A}}$ and $\mathsf{MQ}_{\text{B}}$, whose Coulomb branches encode the maximal A- and B- branches, with RG flows captured by the decay and fission algorithm and index/Hilbert-series cross-checks. They extend the framework to $\mathcal{N}=3$ theories by deriving a magnetic quiver for each maximal branch from brane systems with $(p,q)$ 5-branes, including non-Lagrangian $(p,q)$-brane theories, thereby enabling systematic predictions for maximal-branch geometry and Higgsing patterns. The work provides a versatile, unified method to study moduli spaces of 3d CSM theories, connecting brane intuition, quiver technology, and exact invariants to reveal rich branch structures and IR dynamics across a broad class of theories.
Abstract
Three-dimensional supersymmetric Chern-Simons Matter (CSM) theories typically preserve $ \mathcal{N}=3$ supersymmetry but can exhibit enhanced $\mathcal{N}=4$ supersymmetry under special conditions. A detailed understanding of the moduli space of CSM theories, however, has remained elusive. This paper addresses this gap by systematically analysing the maximal branches of the moduli space of $\mathcal{N}=3$ and $\mathcal{N}=4$ CSM realised via Type IIB brane constructions. Firstly, for $\mathcal{N}=4$ theories with Chern-Simons levels equal $1$, the $\mathrm{SL}(2,\mathbb{Z})$ dualisation algorithm is employed to construct dual Lagrangian 3d $\mathcal{N}=4$ theories without CS terms. This allows the full moduli space to be determined using quiver algorithms that compute Higgs and Coulomb branch Hasse diagrams and associated RG flows. Secondly, for $\mathcal{N}=4$ theories with CS-levels greater $1$, where $\mathrm{SL}(2,\mathbb{Z})$ dualisation does not yield CS-free Lagrangians, a new prescription is introduced to derive two magnetic quivers, $\mathsf{MQ}_A $ and $\mathsf{MQ}_B$, whose Coulomb branches capture the maximal A and B branches of the original $\mathcal{N}=4$ CSM theory. Applying the decay and fission algorithm to $ \mathsf{MQ}_{A/B}$ then enables the systematic analysis of A/B branch RG flows and their geometric structures. Thirdly, for $\mathcal{N}=3$ CSM theories, one magnetic quiver for each maximal (hyper-Kähler) branch is derived from the brane system. This provides an efficient and comprehensive characterisation of these previously scarcely studied features.
