# An Index for 2D field theories with large N=4 superconformal symmetry

**Authors:** Sergei Gukov, Emil Martinec, Gregory Moore, Andrew Strominger  
**arXiv:** [hep-th/0404023](https://arxiv.org/abs/hep-th/0404023)  
**Date:** 2004-04-02  
**Summary page:** https://www.summarizepaper.com/fr/paper/hep-th--0404023v2/

## Abstract

We consider families of theories with large N=4 superconformal symmetry. We define an index generalizing the elliptic genus of theories with N=2 symmetry. In contrast to the N=2 case, the new index constrains part of the non-BPS spectrum. Motivated by aspects of the AdS/CFT correspondence we study the index in the examples of symmetric product theories. We give a physical interpretation of the Hecke operators which appear in the expressions for partition functions of such theories. Finally, we compute the index for a nontrivial example of a symmetric product theory.