Large N techniques for Nekrasov partition functions and AGT conjecture
Abstract
The AGT conjecture relates \mathcal{N}=2 4d SUSY gauge theories to 2d CFTs. Matrix model techniques can be used to investigate both sides of this relation. The large N limit refers here to the size of Young tableaux in the expression of the gauge theory partition function. It corresponds to the vanishing of Omega-background equivariant deformation parameters, and should not be confused with the t'Hooft expansion at large number of colors. In this paper, a saddle point approach is employed to study the Nekrasov-Shatashvili limit of the gauge theory, leading to define beta-deformed, or quantized, Seiberg-Witten curve and differential form. Then this formalism is compared to the large N limit of the Dijkgraaf-Vafa beta-ensemble. A transformation law relating the wave functions appearing at both sides of the conjecture is proposed. It implies a transformation of the Seiberg-Witten 1-form in agreement with the definition specified earlier. As a side result, a remarkable property of \mathcal{N}=2 theories emerged: the instanton contribution to the partition function can be determined from the perturbative term analysis.
Cite
@article{arxiv.1212.4972,
title = {Large N techniques for Nekrasov partition functions and AGT conjecture},
author = {Jean-Emile Bourgine},
journal= {arXiv preprint arXiv:1212.4972},
year = {2013}
}
Comments
31 pages, v4 arxiv numbers added to the bibliography