Gauge-stringy instantons in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ \mathcal{N} $\end{document} = 2 U(N) gauge theories

Using D3/D(−1) brane set-up in type IIB string theory we introduce gaugestringy instantons in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ \mathcal{N} $\end{document} = 2 U(N ) supersymmetry theories with one matter multiplet in symmetric representation. In addition to the gauge and stringy moduli there exist extra zero modes that we refer to as “gauge-stringy” moduli. We show that the measure of the moduli space in this model becomes dimensionless for arbitary N when the gauge instanton charge kg is equal to the stringy instanton charge ks. This property of gauge-stringy instantons leads to having equal contributions from all instanton charges ks = kg ≡ k in the effective action. We derive the gauge-stringy instanton partition function and calculate the corrections to the prepotential due to k = 1, 2 gauge-stringy instanton charges. As a by-product the partition function for gauge k-instanton is obtained which coincides with the result from the standard ADHM construction.