Observations On The Moduli Space Of Two Dimensional String Theory

TL;DR

This paper investigates the moduli space of two-dimensional fermionic string theories, revealing new theories with chiral GSO projections and exploring their compactifications, including the emergence of noncritical superstrings.

Contribution

It introduces two new two-dimensional string theories with chiral GSO projections and maps their moduli space, including novel compactifications and special points with noncritical superstrings.

Findings

Identification of two new 2D string theories with chiral GSO projections.

Mapping of the moduli space with eight lines of theories.

Discovery of noncritical superstrings at special points.

Abstract

We explore the moduli space of the two dimensional fermionic string with linear dilaton. In addition to the known 0A and 0B theories, there are two theories with chiral GSO projections, which we call IIA and IIB. They are similar to the IIA and IIB theories of ten dimensions, but are constructed with a different GSO projection. Compactifying these theories on various twisted circles leads to eight lines of theories. Three of them, 0A on a circle, super-affine 0A and super-affine 0B are known. The other five lines of theories are new. At special points on two of them we find the noncritical superstring.