Branes and the Kraft-Procesi transition: classical case
Santiago Cabrera, Amihay Hanany
TL;DR
This work extends Kraft-Procesi transitions from sl(n) to the full set of classical Lie algebras by embedding Type IIB brane configurations with orientifold O3-planes, thereby constructing orthosymplectic quivers whose Higgs branches are closures of nilpotent orbits. It develops the partition-duality machinery (transpose, B/C/D-collapse, d_{LS}, d_{BV}) and translates Brieskorn-Slodowy slices into explicit brane moves, S-dualities, and quiver readouts. The authors provide a comprehensive matrix formalism that encodes brane data and systematizes KP transitions across so(2n), so(2n+1), and sp(n) sectors, including D_n, A_{2n-1}, and A_{2n-1}∪A_{2n-1} singularities and their minimal counterparts. They also illustrate the framework with detailed SO(4) and SO(5) examples, derive Hasse diagrams for the corresponding orbit closures, and discuss T_{ρ}(G) theories and mirror-symmetric aspects within orthosymplectic settings. The results unify geometric invariant theory with brane dynamics, offering a practical toolkit for identifying slices and transverse structures in moduli spaces of 3d N=4 theories and suggesting directions for refined Hilbert-series and complete mirror descriptions.
Abstract
Moduli spaces of a large set of $3d$ $\mathcal{N}=4$ effective gauge theories are known to be closures of nilpotent orbits. This set of theories has recently acquired a special status, due to Namikawa's theorem. As a consequence of this theorem, closures of nilpotent orbits are the simplest non-trivial moduli spaces that can be found in three dimensional theories with eight supercharges. In the early 80's mathematicians Hanspeter Kraft and Claudio Procesi characterized an inclusion relation between nilpotent orbit closures of the same classical Lie algebra. We recently showed a physical realization of their work in terms of the motion of D3-branes on the Type IIB superstring embedding of the effective gauge theories. This analysis is restricted to A-type Lie algebras. The present note expands our previous discussion to the remaining classical cases: orthogonal and symplectic algebras. In order to do so we introduce O3-planes in the superstring description. We also find a brane realization for the mathematical map between two partitions of the same integer number known as "collapse". Another result is that basic Kraft-Procesi transitions turn out to be described by the moduli space of orthosymplectic quivers with varying boundary conditions.
