Self-Dual Nonsupersymmetric Type II String Compactifications

TL;DR

This paper explores dual descriptions of certain nonsupersymmetric type II string orbifolds with vanishing cosmological constant, revealing weakly coupled duals that maintain perturbative cancellations even at strong coupling.

Contribution

It demonstrates how Sen and Vafa's techniques can construct dual type II models for nonsupersymmetric orbifolds, including cases without heterotic duals, and analyzes their strong-weak coupling relationships.

Findings

Dual type II models exchange the string coupling and T^2 volume.

Strongly coupled limits have weakly coupled duals with similar perturbative cancellations.

Some models lack a weakly coupled heterotic dual.

Abstract

It has recently been proposed that certain nonsupersymmetric type II orbifolds have vanishing perturbative contributions to the cosmological constant. We show that techniques of Sen and Vafa allow one to construct dual type II descriptions of these models (some of which have no weakly coupled heterotic dual). The dual type II models are given by the same orbifolds with the string coupling $S$ and a $T^2$ volume $T$ exchanged. This allows us to argue that in various strongly coupled limits of the original type II models, there are weakly coupled duals which exhibit the same perturbative cancellations as the original models.