Type IIB tensionless superstrings in a pp-wave background

TL;DR

This paper solves the tensionless superstring in a pp-wave background, revealing a highly degenerate spectrum, and demonstrates it as a limit of the quantized tensile IIB string theory, contrasting with other backgrounds.

Contribution

It provides the first exact solution for tensionless superstrings in a broad class of pp-wave backgrounds and connects it to the tensile theory as a consistent limit.

Findings

Hugely degenerate spectrum for tensionless superstrings in pp-wave backgrounds

Solution derived as a limit of quantized tensile IIB strings

Contrasts with other backgrounds where such a limit is not consistent

Abstract

We solve the tensionless string in a constant plane wave background and obtain a hugely degenerate spectrum. This is the case for a large class of plane wave backgrounds. We show that the solution can also be derived as a consistent limit of the quantized tensile theory of IIB strings in a pp-wave. This is in contrast to the situation for several other backgrounds.