Quiver CFT at strong coupling
The circular Wilson loop in the two-node quiver CFT is computed at large-N and strong 't Hooft coupling by solving the localization matrix model.
arXiv subjects
Publications and source records attributed to K. Zarembo.
The circular Wilson loop in the two-node quiver CFT is computed at large-N and strong 't Hooft coupling by solving the localization matrix model.
Electrons in graphene exhibit hydrodynamic behavior in a certain range of temperatures. We indicate that electric current in this regime can result in cooling of electron fluid due to the Joule-Thomson effect. Cooling occurs in the Fermi liquid regime, while for the Dirac fluid the effect results in heating.
Relatively low crossover temperature suggests that chiral symmetry restoration in QCD may well be described within the low-energy effective theory. The shape of the pseudocritical line in the T-mu plane is estimated within this assumption. No critical endpoint is found for physical values of quark masses.
The N=2* theory (mass deformation of N=4 Super-Yang-Mills) undergoes an infinite number of quantum phase transitions in the large-N limit. The phase structure and critical behavior can be analyzed with the help of supersymmetric localization, which reduces the problem to an effective matrix model. We study its strong-coupling phase.
This is a write-up of lectures on integrable sigma-models, which covers the following topics: (1) Homogeneous spaces, (2) Classical integrability of sigma-models in two dimensions, (3) Topological terms, (4) Background-field method and beta-function, (5) S-matrix bootstrap in the O(N) model, (6) Supersymmetric cosets and strings on AdS(d)xX.
We consider level crossing in a matrix family $H=H_0+λV$ where $H_0$ is a fixed $N\times N$ matrix and $V$ belongs to one of the standard Gaussian random matrix ensembles. We study the probability distribution of level crossing points in the complex plane of $λ$, for which we obtain a number of exact, asymptotic and approximate formulas.
Partial Neel states are generalizations of the ordinary Neel (classical anti-ferromagnet) state that can have arbitrary integer spin. We study overlaps of these states with Bethe states. We first identify this overlap with a partial version of reflecting-boundary domain-wall partition function, and then derive various determinant representations for off-shell and on-shell Bethe states.
We review how localization is used to probe holographic duality and, more generally, non-perturbative dynamics of four-dimensional N=2 supersymmetric gauge theories in the planar large-N limit.
Using exact results obtained from localization on S^4, we explore the large N limit of N=2 super-Yang-Mills theories with massive matter multiplets. We focus on three cases: N=2* theory, describing a massive hypermultiplet in the adjoint representation, SU(N) super-Yang-Mills with 2N massive hypermultiplets in the fundamental, and super-QCD with massive quarks. When the radius of the four-sphere is sent to infinity the theories at hand are described by solvable matrix models, which exhibit a number of interesting phenomena including quantum phase transitions at finite 't Hooft coupling.
We study N=2 Yang-Mills theory on S^4 in the large-N limit. We find that on a large sphere Wilson loops obey a perimeter law and that the free energy grows quadratically with the radius of the sphere. We also comment on the large-N limit of the N=2* theory, and on the free energy in N=2 and N=4 superconformal theories.
The spectrum of an infinite spinning string in AdS(5) does not precisely match the spectrum of dual gauge theory operators, interpolated to the strong coupling regime with the help of Bethe-ansatz equations. We show that the mismatch is due to interactions in the string sigma-model which cannot be neglected even at asymptotically large 't Hooft coupling.
The giant magnons are classical solitons of the O(N) sigma-model, which play an important role in the AdS/CFT correspondence. We study quantum giant magnons first at large N and then exactly using Bethe Ansatz, where giant magnons can be interpreted as holes in the Fermi sea. We also identify a solvable limit of Bethe Ansatz in which it describes a weakly-interacting Bose gas at zero temperature. The examples include the O(N) model at large N, weakly interacting non-linear Schrodinger model, and nearly isotropic XXZ spin chain in the magnetic field.
We set up a general scheme to resum ladder diagrams for the quark-anti-quark potential in N=4 super-Yang-Mills theory, and do explicit calculations at the next-to-leading order. The results perfectly agree with string theory in AdS(5)xS(5) when continued to strong coupling, in spite of a potential order-of-limits problem.
We compute the expectation value of the circular Wilson loop in N=2 supersymmetric Yang-Mills theory with N_f=2N hypermultiplets. Our results indicate that the string tension in the dual string theory scales as the logarithm of the 't Hooft coupling.
We consider the type IIB Green-Schwarz superstring theory on AdS(2)xS(2)xT(6) supported by homogeneous Ramond-Ramond 5-form flux and its type IIA T-duals. One motivation is to understand the solution of this theory based on integrability. This background is a limit of a 1/4 supersymmetric supergravity solution describing four intersecting D3-branes and represents a consistent embedding of AdS(2)xS(2) into critical superstring theory. Its AdS(2)xS(2) part with corresponding fermions can be described by a classically integrable PSU(1,1|2)/SO(1,1)xU(1) supercoset sigma-model. We point out that since the RR 5-form field has non-zero components along the 6-torus directions one cannot, in general, factorize the 10d superstring theory into the supercoset part plus 6 bosons and 6 additional massless fermions. Still, we demonstrate that the full superstring model (i) is classically integrable, at least to quadratic order in fermions, and (ii) admits a consistent classical truncation to the supercoset part. Following the analogy with other integrable backgrounds and starting with the finite-gap equations of the PSU(1,1|2)/SO(1,1)xU(1) supercoset we propose a set of asymptotic Bethe ansatz equations for a subset of the quantum string states.
Many Ramond-Ramond backgrounds which arise in the AdS/CFT correspondence are described by integrable sigma-models. The equations of motion for classical spinning strings in these backgrounds are exactly solvable by finite-gap integration techniques. We review the finite-gap integral equations and algebraic curves for coset sigma-models, and then apply the results to the AdS(d+1) backgrounds with d=4,3,2,1.
The AdS(4)/CFT(3) duality is a new example of an integrable and exactly solvable AdS/CFT system. There is, however, a puzzling mismatch between the number of degrees of freedom used in the exact solution (4B+4F scattering states) and 8B+8F transverse oscillation modes of critical superstring theory. We offer a resolution of this puzzle by arguing that half of the string modes dissolve in the continuum of two-particle states once alpha' corrections are taken into account. We also check that the conjectured exact S-matrix of AdS(4)/CFT(3) agrees with the tree-level worldsheet calculation.
We calculate the holographic three-point functions in N = 4 super-Yang-Mills theory in the case when two of the operators are semiclassical and one is dual to a supergravity mode. We further discuss the transition to the regime when all three operators are semiclassical.