Geometry of Decoupled Fields

In this talk I will discuss aspects of decoupling fields that appear in the engineering of 4d SCFTs from compactifications of 6d (1,0) SCFTs of A_(N-1) type.  By studying various ways of constructing the anomaly polynomial for the 4d theory, it is possible to account for decoupling fields when the 6d SCFT is compactified on a Riemann surface.  I will also discuss their geometric origin and their role along the RG flow