Cherkis bow varieties and Coulomb branches of quiver gauge theories of affine type $A$
Hiraku Nakajima, Yuuya Takayama
TL;DR
The work establishes that Coulomb branches of framed quiver gauge theories of affine type $A$ are Cherkis bow varieties, linking the physics-driven Coulomb construction to a robust algebro-geometric model. It provides a detailed quiver description of bow varieties, proves a factorization property, and constructs a birational isomorphism to the Coulomb branch, yielding normal, stratified, and semismall structures. Under balanced dimensions, bow varieties coincide with Na-quiver varieties, and the authors develop deformation/resolution pictures, a collapsing morphism to chainsaw quiver varieties, and explicit local models. The paper further explores Hanany-Witten transitions and 3d mirror symmetry, situating bow/Coulomb structures within brane dualities and broadening the toolkit for studying moduli of instantons on Taub-NUT spaces and related hyper-Kähler geometries.
Abstract
We show that Coulomb branches of quiver gauge theories of affine type $A$ are Cherkis bow varieties, which have been introduced as ADHM type description of moduli space of instantons on the Taub-NUT space equivariant under a cyclic group action.
