S-duality Improved Superstring Perturbation Theory

TL;DR

This paper investigates using S-duality to create a smooth interpolating formula that accurately estimates the mass of a non-BPS state across all coupling strengths in string theory.

Contribution

It introduces a method to construct an interpolating function that matches perturbative expansions at both weak and strong coupling ends, improving mass estimates in string theory.

Findings

Interpolating formula estimates mass within 10% accuracy across all couplings.

Application to SO(32) heterotic/type I string theory shows promising results.

One-loop corrections improve the mass prediction accuracy.

Abstract

Strong - weak coupling duality in string theory allows us to compute physical quantities both at the weak coupling end and at the strong coupling end. Furthermore perturbative string theory can be used to compute corrections to the leading order formula at both ends. We explore the possibility of constructing a smooth interpolating formula that agrees with the perturbation expansion at both ends and leads to a fairly accurate determination of the quantity in consideration over the entire range of the coupling constant. We apply this to study the mass of the stable non-BPS state in SO(32) heterotic / type I string theory with encouraging results. In particular our result suggests that after taking into account one loop corrections to the mass in the heterotic and type I string theory, the interpolating function determines the mass within 10% accuracy over the entire range of coupling constant.