Classification of the N=2, Z2 X Z2-symmetric type II orbifolds and their type II asymmetric duals

TL;DR

This paper classifies N=2, Z2 x Z2 symmetric orbifolds in type II string theories, explores their moduli space, and constructs dual pairs to study non-perturbative effects and gravitational corrections.

Contribution

It provides a complete classification of symmetric N=2 orbifolds and introduces new dual pairs, enhancing understanding of non-perturbative phenomena in type II string theories.

Findings

Classification of all symmetric N=2 Z2 x Z2 orbifolds

Construction of dual pairs related non-perturbatively

Analysis of gravitational corrections in these models

Abstract

Using free world-sheet fermions, we construct and classify all the N=2, Z2 X Z2 four-dimensional orbifolds of the type IIA/B strings for which the orbifold projections act symmetrically on the left and right movers. We study the deformations of these models out of the fermionic point, deriving the partition functions at a generic point in the moduli of the internal torus T6=T2 X T2 X T2. We investigate some of their perturbative and non-perturbative dualities and construct new dual pairs of type IIA/type II asymmetric orbifolds, which are related non-perturbatively and allow us to gain insight into some of the non-perturbative properties of the type IIA/B strings in four dimensions. In particular, we consider some of the (non-)perturbative gravitational corrections.