Strings in Plane Wave Backgrounds Revisited

TL;DR

This paper investigates string theory in plane wave backgrounds, presenting a new singularity example, constructing a 4-tachyon scattering amplitude, and analyzing the spectrum, which matches flat space-time results.

Contribution

It introduces a novel example of string-theoretic singularity in a nonsingular spacetime and constructs the corresponding scattering amplitude.

Findings

Spectrum matches flat space-time results

Constructed 4-tachyon scattering amplitude

Identified a new string-theoretic singularity

Abstract

String theory in an exact plane wave background is explored. A new example of singularity in the sense of string theory for nonsingular spacetime metric is presented. The 4-tachyon scattering amplitude is constructed. The spectrum of states found from the poles in the factorization turns out to be equivalent to that of the theory in flat space-time. The massless vertex operator is obtained from the residue of the first order pole.