ceff for 3D 𝒩=2 theories

Based on the observed behavior of the superconformal index in three-dimensional [Formula: see text] theories, we propose a quantity that can be considered as an analogue of the “effective central charge.” We discuss the general properties of this quantity and ways of computing it in a variety of different theories, including simple Lagrangian theories as well as more interesting strongly coupled examples that come from 3d-3d correspondence.