Bow varieties, introduced by S. Cherkis in 2011, form a class of varieties that unify and generalize several important constructions. For instance, they include Nakajima’s quiver varieties and the Coulomb branches of affine type A quiver gauge theories (in the sense of Braverman–Finkelberg–Nakajima) as special cases.

I will start with the definition of Hanany–Witten configurations of branes. Then, I will introduce bow varieties of affine (or finite) type A as moduli spaces attached to such brane configurations, following Nakajima--Takayama's approach. This perspective motivates the interpretation of bow varieties as Higgs and Coulomb branches in 3d N=4 supersymmetric quantum field theories. I will therefore explain how to recover Nakajima quiver varieties and Coulomb branches of affine type A as special cases of bow varieties. Finally, if time permits, I will present recent results showing that the non-emptiness of bow varieties is equivalent to the preservation of supersymmetry in the corresponding brane configurations.