Power Towers of String Instantons for N=1 Vacua

TL;DR

This paper investigates novel poly-instanton corrections in N=1 string compactifications, refining instanton calculus and revealing a power tower proliferation of corrections in certain string vacua.

Contribution

It introduces and analyzes poly-instanton corrections to holomorphic couplings, providing explicit calculations and duality comparisons in Type I and heterotic string models.

Findings

Identification of poly-instanton corrections in N=1 vacua

Refined D-brane instanton calculus for gauge kinetic functions

Evidence of power tower proliferation of instanton effects

Abstract

We provide arguments for the existence of novel hereinafter called poly-instanton corrections to holomorphic couplings in four-dimensional N=1 supersymmetric string compactifications. After refining quantitatively the D-brane instanton calculus for corrections to the gauge kinetic function, we explicitly apply it to the Type I toroidal orbifold defined in arXiv:0710.3080 and compare the results to the proposed heterotic S-dual model. This leads us to the intriguing conclusion that N=1 string vacua feature a power tower like proliferation of instanton corrections.