arXiv subjects

Alexei Yung

Publications and source records attributed to Alexei Yung.

21 records · Page 2Linked to original sources

arXiv1999

Vortices on the Higgs Branch of the Seiberg-Witten Theory

We study the mechanism of confinement via formation of Abrikosov-Nielsen-Olesen vortices on the Higgs branch of N=2 supersymmetric SU(2) gauge theory with massive fundamental matter. Higgs branch represents a limiting case of superconductor of type I with vanishing Higgs mass. We show that in this limit vortices still exist although they become logarithmically "thick". Because of this the confining potential is not linear any longer. It behaves as $L/\log L$ with a distance $L$ between confining heavy charges (monopoles). This new confining regime can occur only in supersymmetric theories. We also address the problem of quantum stability of vortices. To this end we develop string representation for a vortex and use it to argue that vortices remain stable.

hep-th↗

arXiv1997

Higher Derivative Terms in the Effective Action of N=2 SUSY QCD from Instantons

We consider N=2 SUSY QCD with gauge group SU(2) and N_f flavours of matter with nonzero mass. Using the method of the instanton-induced effective vertex we calculate higher derivative corrections to the Seiberg-Witten result in the momentum expansion of the low energy effective Lagrangian in various regions of the modular space. Then we focus on a certain higher derivative operator on the Higgs branch. We show that the singular behavior of this operator comes from values of mass of matter at which charge singularity on the Coulomb branch collides with the monopole or dyon one. Given the behavior of this operator at weak coupling coming from instantons as well as its behavior near points of colliding singularities we find the exact solution for this operator.

hep-th↗

arXiv1996

Instanton-induced Effective Lagrangian in the Seiberg-Witten Model

The N=2 supersymmetric gauge theory with gauge group SU(2) is considered. The instanton field is calculated explicitly using the superfield formalism. The instanton-induced effects are encoded in the effective vertex in the Lagrangian. This vertex produces the large distance expansion of the low energy effective Lagrangian in derivatives of fields. The leading term in this expansion coincides with the one-instanton-induced term of the Seiberg-Witten exact solution of the model. All orders of corrections in derivatives of fields are also calculated.

hep-th↗