An important recent development in geometric representation theory (with close connections to quiver varieties) is the mathematical approach to Coulomb branches, developed by Alexander Braverman, Michael Finkelberg, and Hiraku Nakajima.  During this focus week, Finkelberg and Nakajima will give mini-courses on specific aspects of this theory, namely Shifted quantum affine algebras and Cherkis bow varieties.  A number of complementary lectures by other visitors will also be scheduled. Participants who wish to give a lecture during this week should contact Joel Kamnitzer (jkamnitz@math.toronto.edu) with a proposed topic.