String Duality and Non-supersymmetric Strings

TL;DR

This paper explores a class of non-supersymmetric string theories with vanishing cosmological constant at perturbative levels and investigates their dual heterotic descriptions, revealing non-perturbative effects and spectrum mismatches.

Contribution

It introduces a dual heterotic framework for non-supersymmetric strings with vanishing perturbative cosmological constant, highlighting non-perturbative phenomena.

Findings

Perturbative cosmological constant vanishes at first two orders.

Dual heterotic theory exhibits a non-zero, non-perturbative cosmological constant.

Mismatch between Bose and Fermi degrees of freedom in non-perturbative D-brane spectrum.

Abstract

In recent work Kachru, Kumar and Silverstein introduced a special class of non-supersymmetric type II string theories in which the cosmological constant vanishes at the first two orders of perturbation theory. Heuristic arguments suggest the cosmological constant may vanish in these theories to all orders in perturbation theory leading to a flat potential for the dilaton. A slight variant of their model can be described in terms of a dual heterotic theory. The dual theory has a non-zero cosmological constant which is non-perturbative in the coupling of the original type II theory. The dual theory also predicts a mismatch between Bose and Fermi degrees of freedom in the non-perturbative D-brane spectrum of the type II theory.