A Note on Low-Dimensional String Compactifications

TL;DR

This paper investigates supersymmetric compactifications of type II strings on eightfolds to two dimensions, confirming anomaly freedom, analyzing T-duality implications, and discussing relations to M-Theory orientifolds.

Contribution

It demonstrates the anomaly-free nature of type IIB on eightfolds and explores T-duality and M-Theory orientifold relations in two-dimensional compactifications.

Findings

Type IIB on eightfolds is free of gravitational anomalies.

T-duality requires vacuum momentum in circle compactifications.

Relations between IIB compactifications and M-Theory orientifolds are clarified.

Abstract

We study supersymmetric compactifications of type II strings on eightfolds to two dimensions. It is demonstrated that the type IIB string on an eightfold is free of gravitational anomalies. T-duality requires that this theory when further compactified on a circle must have a vacuum momentum; this is explicitly shown to be present and to have the right value. A subtlety in the relation of IIB compactifications and M-Theory orientifolds to two dimensions is pointed out.