N=2 Superstrings with (1,2m) Spacetime Signature

TL;DR

This paper studies an N=2 superstring in higher dimensions with a specific spacetime signature, revealing a coordinate-freezing phenomenon that effectively removes one time dimension, and suggests the theory is ghost free.

Contribution

It introduces a novel background charge configuration in N=2 superstrings that results in a coordinate-freezing effect, altering the effective spacetime signature.

Findings

The coordinate-freezing constrains momentum in one time direction.

The theory exhibits a (1,d-2) spacetime signature.

Low-lying states are ghost free.

Abstract

We show that the $N=2$ superstring in $d=2D\ge6$ real dimensions, with criticality achieved by including background charges in the two real time directions, exhibits a ``coordinate-freezing'' phenomenon, whereby the momentum in one of the two time directions is constrained to take a specific value for each physical state. This effectively removes this time direction as a physical coordinate, leaving the theory with $(1,d-2)$ real spacetime signature. Norm calculations for low-lying physical states suggest that the theory is ghost free.