Stringy Instantons and Cascading Quivers

TL;DR

This paper explores how stringy instantons in quiver gauge theories at Calabi-Yau singularities can be understood both as novel string effects and as traditional gauge theory phenomena through RG cascades, revealing their dual nature.

Contribution

It demonstrates that stringy instantons can be reinterpreted as gauge theory effects via RG cascades, bridging stringy and field theory perspectives in quiver gauge theories.

Findings

Stringy instantons can be viewed as gauge theory effects after RG cascade.

Instanton contributions can originate from strong coupling dynamics.

Both stringy and gauge theory interpretations are valid for certain instantons.

Abstract

D-brane instantons can perturb the quantum field theories on space-time filling D-branes by interesting operators. In some cases, these D-brane instantons are novel "stringy" effects (not interpretable directly as instanton effects in the low-energy quantum field theory), while in others the D-brane instantons can be directly interpreted as field theory effects. In this note, we describe a situation where both perspectives are available, by studying stringy instantons in quivers which arise at simple Calabi-Yau singularities. We show that a stringy instanton which wraps an unoccupied node of the quiver, and gives rise to a non-perturbative mass in the space-time field theory, can be reinterpreted as a conventional gauge theory effect by going up in an appropriate renormalization group cascade. Interestingly, in the cascade, the contribution of the stringy instanton does not come from gauge theory instantons but from strong coupling dynamics.