String-String Duality in Ten Dimensions

TL;DR

This paper explores dualities between different ten-dimensional string theories, providing evidence that heterotic and type I strings are equivalent and that type IIB string theory is self-dual, enhancing understanding of string theory unification.

Contribution

It offers new insights into string dualities, specifically demonstrating the heterotic/type I equivalence and supporting the self-duality of type IIB string theory.

Findings

Heterotic string is a soliton of type I superstring.

Type IIB string exhibits self-duality with a dual description.

Dual strings appear as Ramond-Ramond solitons.

Abstract

The heterotic string occurs as a soliton of the type I superstring in ten dimensions, supporting the conjecture that these two theories are equivalent. The conjecture that the type IIB string is self-dual, with the strong coupling dynamics described by a dual type IIB theory, is supported by the occurrence of the dual string as a Ramond-Ramond soliton of the weakly-coupled theory.