From the Type I String to M-theory: A Continuous Connection

TL;DR

This paper constructs an explicit dual connecting theory that links the Type I string to M-theory, revealing a continuous connection and providing new insights into D-brane bound states.

Contribution

It presents a novel explicit construction of the dual connecting theory between Type I string and M-theory, and shows how the $E_8\times E_8$ heterotic string appears as a D-string soliton.

Findings

Established a continuous dual connection between Type I string and M-theory.

Realized the $E_8\times E_8$ heterotic string as a D-string soliton.

Provided an alternative D-brane bound state description.

Abstract

It is well-known that the SO(32) and $E_8\times E_8$ heterotic strings can be continuously connected to each other in nine dimensions. Since the strong-coupling duals of these theories are respectively the SO(32) Type I theory and M-theory compactified on a line segment, there should be a corresponding continuous connection between the Type I string and M-theory. In this paper, we give an explicit construction of this dual connecting theory. Our construction also enables us to realize the $E_8\times E_8$ heterotic string as a D-string soliton of the Type I theory. This provides a useful alternative description of the D-brane bound states previously discussed from a Type I' point of view.