N=2 supersymmetric gauge theory on connected sums of $S^2\times S^2$

TL;DR

This paper constructs and analyzes 4D N=2 supersymmetric gauge theories on connected sums of S^2×S^2, deriving their partition functions through dimensional reduction from 5D theories on toric Sasaki-Einstein manifolds, extending Pestun's results.

Contribution

It introduces a method to build 4D N=2 theories on complex topologies and computes their partition functions, generalizing known results to new manifold classes.

Findings

Partition functions include instanton and anti-instanton contributions.

Conditions for dimensional reduction on toric manifolds are established.

Partial classification of resulting 4D manifolds is provided.

Abstract

We construct 4D $\mathcal{N}=2$ theories on an infinite family of 4D toric manifolds with the topology of connected sums of $S^2 \times S^2$. These theories are constructed through the dimensional reduction along a non-trivial $U(1)$-fiber of 5D theories on toric Sasaki-Einstein manifolds. We discuss the conditions under which such reductions can be carried out and give a partial classification result of the resulting 4D manifolds. We calculate the partition functions of these 4D theories and they involve both instanton and anti-instanton contributions, thus generalizing Pestun's famous result on $S^4$.