Non-Perturbative States in Superstring Theories

TL;DR

This paper explores non-perturbative BPS states in superstring theories, constructing new classes of such states in type II strings, analyzing their intersections, and discussing phenomenological implications like black hole corrections and superpotentials.

Contribution

It introduces a broad class of BPS-saturated states in type II string theories and analyzes their intersections, extending previous work on heterotic strings.

Findings

Constructed a large class of BPS states parametrized by four parameters

Analyzed orthogonal and non-orthogonal intersections of non-perturbative states

Discussed string effects on black holes and supergravity superpotentials

Abstract

Massless BPS-saturated states in toroidally compactified heterotic string were discussed first. Then, I constructed a large class of BPS-saturated states of toroidally compactified type II string theories. They were parametrized by four independent parameters. Both orthogonal and non-orthogonal intersections of non-perturbative states in the corresponding ten dimensional theories were discussed. Phenomenologically, I considered the string effect in the form of threshold corrections on dilatonic charged black holes, and the superpotential of N=1 supergravity theory