A Note on Orientifolds and Dualities of Type 0B String Theory

TL;DR

This paper extends the construction of non-tachyonic orientifolds in type 0B string theory to non-supersymmetric four and six-dimensional models, presenting anomaly-free spectra and exploring potential dualities.

Contribution

It introduces new non-supersymmetric orientifold models in four and six dimensions with anomaly-free spectra and discusses possible strong coupling duals.

Findings

Constructed a 4D non-tachyonic orientifold with chiral anomaly-free spectrum

Developed a 6D tachyon-free model with only D5 branes

Speculated on dual models at strong coupling

Abstract

We generalize the construction of four dimensional non-tachyonic orientifolds of type 0B string theory to non-supersymmetric backgrounds. We construct a four dimensional model containing self-dual D3 and D9-branes and leading to a chiral anomaly-free massless spectrum. Moreover, we discuss a further tachyon-free six dimensional model with only D5 branes. Eventually, we speculate about strong coupling dual models of the ten-dimensional orientifolds of type 0B.