Non-Perturbative Solutions of String Theory in Gravitational Backgrounds

TL;DR

This paper identifies specific stable, topological soliton solutions in bosonic string theory within static gravitational backgrounds, which dominate the path integral due to their zero action and background independence.

Contribution

It demonstrates that only left-movers or right-movers form background-independent non-perturbative solutions in static metrics, revealing their topological and stable nature.

Findings

Solutions are stable topological solitons.

Action vanishes for these solutions.

They dominate the path integral in quantization.

Abstract

We study bosonic string theory in a gravitational background. We show that either left-movers or right-movers are the only background independent non-perturbative solutions of the field equations for an arbitrary static metric. They are stable and have a conserved topological charge being therefore topological solitons. The action vanishes for these solutions and hence they provide the dominating contribution in a path integral quantization