String Loop Threshold Corrections \break For ${\bf Z}_N$ Coxeter Orbifolds

TL;DR

This paper studies how string loop threshold corrections to gauge couplings depend on moduli in specific ${f Z}_N$ Coxeter orbifolds where certain twisted sectors have fixed planes that cannot be decomposed into a direct sum of a four-torus and a two-torus.

Contribution

It analyzes the moduli dependence of threshold corrections in orbifolds with fixed planes that defy standard torus decomposition, extending understanding of string loop effects.

Findings

Identifies the moduli dependence in complex orbifold sectors.

Provides explicit calculations for non-decomposable fixed planes.

Enhances the understanding of gauge coupling corrections in string theory.

Abstract

The moduli dependence of string loop threshold corrections to gauge coupling constants is investigated for those ${\bf Z}_N$ Coxeter orbifolds with the property that some twisted sectors have fixed planes for which the six-torus ${\bf T}_6$ can not be decomposed into a direct sum ${\bf T}_4 \bigoplus{\bf T}_2$ with the fixed plane lying in ${\bf T}_2.$