Instanton operators and symmetry enhancement in 5d supersymmetric quiver gauge theories

Understand

We consider general 5d $SU(N)$ quiver gauge theories whose nodes form an ADE Dynkin diagram of type $G$.

• Each node has $SU(N_i)$ gauge group of general rank, Chern-Simons level $\kappa_i$ and additional $w_i$ fundamentals.
• When the total flavor number at each node is less than or equal to $2N_i-2|\kappa_i|$, we give general rules under which the symmetries associated to instanton currents are enhanced to $G \times G$ or a subgroup of it in the UV 5d superconformal theory.
• When the total flavor number violates that condition at some of the nodes, further enhancement of flavor symmetries occurs.