On the Low Energy Spectra of the Nonsupersymmetric Heterotic String Theories

TL;DR

This paper investigates how the low energy spectra of certain nonsupersymmetric heterotic string theories can be derived from the Horava--Witten model by imposing specific invariance conditions, expanding the understanding of string theory beyond supersymmetric cases.

Contribution

It proposes a method to generate the spectra of nonsupersymmetric heterotic string vacua from the Horava--Witten model through invariance conditions involving extra operators.

Findings

Successfully demonstrated for E_8 heterotic vacuum

Successfully demonstrated for SO(16)XSO(16) heterotic vacuum

Provides a new approach to connect nonsupersymmetric strings with M-theory

Abstract

The ten dimensional string theories as well as eleven dimensional supergravity are conjectured to arise as limits of a more basic theory, traditionaly dubbed M--theory. This notion is confined to the ten dimensional supersymmetric theories. String theory, however, also contains ten dimensional nonsupersymmetric theories that have not been incorporated into this picture. In this note we explore the possibility of generating the low energy spectra of various nonsupersymmetric heterotic string vacua form the Horava--Witten model. We argue that this can be achieved by imposing on the Horava--Witten model an invariance with respect to some extra operators which identify the orbifold fixed planes in a nontrivial way, and demonstrate it for the E_8 and SO(16)XSO(16) heterotic string vacua in ten dimensions.