Type-I vacua from non-geometric Orbifolds

TL;DR

This paper explores Type-I string vacua derived from non-geometric orbifolds, highlighting their unique properties such as twisted sectors and quantized moduli, which are crucial for their consistency and gauge group structure.

Contribution

It introduces non-geometric orbifold constructions for Type-I vacua and compares open descendants with geometric models, revealing novel features like twisted sectors and quantized moduli.

Findings

Presence of twisted sectors in open-string spectra

Quantized geometric moduli ensure perturbative consistency

Rank reduction of Chan-Paton groups explained by moduli

Abstract

Some examples of Type-I vacua related to non geometric orbifolds are shown. In particular, the open descendants of the diagonal $Z_3$ orbifold are compared with the geometric ones. Although not chiral, these models exhibit some interesting properties, like twisted sectors in the open-string spectra and the presence of ``quantized'' geometric moduli, a key ingredient to ensure their perturbative consistency and to explain the rank reduction of their Chan-Paton groups.