Coulomb branches of $3d$ $\mathcal N=4$ quiver gauge theories and slices   in the affine Grassmannian (with appendices by Alexander Braverman, Michael   Finkelberg, Joel Kamnitzer, Ryosuke Kodera, Hiraku Nakajima, Ben Webster, and   Alex Weekes)
  This is a companion paper of arXiv:1601.03586. We study Coulomb branches of unframed and framed quiver gauge theories of type $ADE$. In the unframed case they are isomorphic to the moduli space of based rational maps from ${\mathbb C}P^1$ to the flag variety. In the framed case they are slices in the affine Grassmannian and their generalization. In the appendix, written jointly with Joel Kamnitzer, Ryosuke Kodera, Ben Webster, and Alex Weekes, we identify the quantized Coulomb branch with the truncated shifted Yangian. 
Alexander Braverman, Michael Finkelberg, Hiraku Nakajima
math.RT hep-th math-ph math.AG math.DG math.MP