Orientifolds of Gepner Models

TL;DR

This paper systematically constructs and analyzes Type II orientifolds based on Gepner models with N=1 supersymmetry, classifying symmetries, solutions, and exploring their moduli space and non-geometric phases.

Contribution

It provides a comprehensive classification of parity symmetries, crosscap states, and solutions for consistent orientifold configurations in Gepner models, including new insights into moduli space and phase transitions.

Findings

Large number of vacua, up to 10^{13}

Identification of chiral solutions in certain models

Matching with large volume regime results

Abstract

We systematically construct and study Type II Orientifolds based on Gepner models which have N=1 supersymmetry in 3+1 dimensions. We classify the parity symmetries and construct the crosscap states. We write down the conditions that a configuration of rational branes must satisfy for consistency (tadpole cancellation and rank constraints) and spacetime supersymmetry. For certain cases, including Type IIB orientifolds of the quintic and a two parameter model, one can find all solutions in this class. Depending on the parity, the number of vacua can be large, of the order of 10^{10}-10^{13}. For other models, it is hard to find all solutions but special solutions can be found -- some of them are chiral. We also make comparison with the large volume regime and obtain a perfect match. Through this study, we find a number of new features of Type II orientifolds, including the structure of moduli space and the change in the type of O-planes under navigation through non-geometric phases.