1/N expansion of circular Wilson loop in N=2 superconformal SU(N) x SU(N) quiver

Localization approach to N = 2 superconformal SU(N) x SU(N) quiver theory leads to a non-Gaussian two-matrix model representation for the expectation value of BPS circular SU(N) Wilson loop W. We study the subleading 1/N-2 term in the large N expansion of W at weak and strong coupling. We concentrate on the case of the symmetric quiver with equal gauge couplings which is equivalent to the Z(2) orbifold of the SU(2N) N = 4 SYM theory. This orbifold gauge theory should be dual to type IIB superstring in AdS(5) x (S-5/Z(2)). We present a string theory argument suggesting that the 1/N-2 term in W in the orbifold theory should have the same strong-coupling asymptotics lambda (3/2) as in the N = 4 SYM case. We support this prediction on the gauge theory side by a numerical study of the localization matrix model. We also find a relation between the 1/N-2 term in the Wilson loop expectation value and the derivative of the free energy of the orbifold gauge theory on 4-sphere.

Automated summary

The article discusses the localization approach to N = 2 superconformal SU(N) x SU(N) quiver theory and the non-Gaussian two-matrix model representation of the BPS circular SU(N) Wilson loop W. The study focuses on the subleading 1/N-2 term in the large N expansion of W at weak and strong coupling, particularly in the case of symmetric quiver with equal gauge couplings. A string theory argument suggests that the 1/N-2 term in this orbifold theory should have similar strong coupling asymptotics as in the N = 4 SYM case, which is supported by numerical studies of the localization matrix model. Additionally, a relation between the 1/N-2 term in the Wilson loop expectation value and the derivative of the free energy of the orbifold gauge theory on a 4-sphere is found.