Flavor symmetry of 5d SCFTs. Part I. General setup

A bstract A large class of 5 d superconformal field theories (SCFTs) can be constructed by integrating out BPS particles from 6 d SCFTs compactified on a circle. We describe a general method for extracting the flavor symmetry of any 5 d SCFT lying in this class. For this purpose, we utilize the geometric engineering of 5 d N N = 1 theories in M-theory, where the flavor symmetry is encoded in a collection of non-compact surfaces.