Localization on three-dimensional manifolds
Brian Willett
TL;DR
This article develops and applies localization for 3d $N=2$ theories on compact manifolds, enabling exact partition functions on $S^3_b$, $S^3_b/\mathbb{Z}_p$, and $S^2\times S^1$ via finite-dimensional matrix models. By embedding theories into rigid 3d supergravity backgrounds, it constructs SUSY-preserving actions on curved spaces and derives explicit $S^3$ and $S^3_b$ partition functions, lens-space generalizations, and the $S^2\times S^1$ index, including operator insertions and real mass/FI deformations. The framework yields powerful checks of dualities, reveals factorization into holomorphic blocks, and connects to the $3d$-3d correspondence and Higgs-branch localization, with broad implications for RG flows ($F$-theorem/maximization), holography (ABJM), and lower-dimensional reductions. Overall, the localization program provides a unifying, exact toolset for understanding strongly coupled 3d $N=2$ dynamics on diverse geometries and their interrelations with topology and higher-dimensional theories.
Abstract
In this review article we describe the localization of three dimensional N=2 supersymmetric theories on compact manifolds, including the squashed sphere, S^3_b, the lens space, S^3_b/Z_p, and S^2 x S^1. We describe how to write supersymmetric actions on these spaces, and then compute the partition functions and other supersymmetric observables by employing the localization argument. We briefly survey some applications of these computations.
