The generalized no-ghost theorem for N=2 SUSY critical strings

TL;DR

This paper proves the no-ghost theorem for N=2 supersymmetric strings in flat space and extends it to arbitrary geometries using N=4 superconformal algebra, identifying physical states as highest weight states.

Contribution

It introduces a generalized no-ghost theorem for N=2 SUSY strings applicable to various geometries leveraging N=4 SCA generators.

Findings

Proof of no-ghost theorem in flat (2,2) space

Generalization to arbitrary geometries using N=4 SCA

Identification of physical states as highest weight states

Abstract

We prove the no-ghost theorem for the N=2 SUSY strings in (2,2) dimensional flat Minkowski space. We propose a generalization of this theorem for an arbitrary geometry of the N=2 SUSY string theory taking advantage of the N=4 SCA generators present in this model. Physical states are found to be the highest weight states of the N=4 SCA.