On the Uniqueness of String Theory

TL;DR

This paper explores the hierarchical relationships among different types of string theories, proposing a unified framework that encompasses bosonic, N=1, and N=2 superstrings as special cases within a broader universal string theory.

Contribution

It introduces a hierarchical perspective on string theories, suggesting a universal theory that includes various string vacua as special cases.

Findings

Bosonic strings as vacua of N=1 superstrings

N=1 superstrings as vacua of N=2 strings

Proposal for a universal string theory

Abstract

We show that bosonic strings may be viewed as a particular class of vacua for N=1 superstrings, and N=1 superstrings may be viewed as a particular class of vacua for N=2 strings. Continuing this line of string hierarchies, we are led to search for a universal string theory which includes all the rest as a special vacuum selection.