arXiv subjects

Sergei L. Lukyanov

Publications and source records attributed to Sergei L. Lukyanov.

26 records · Page 2Linked to original sources

arXiv2014

From Fuchsian differential equations to integrable QFT

We establish an intriguing correspondence between a special set of classical solutions of the modified sinh-Gordon equation (i.e., Hitchin's "self-duality" equations) on a punctured Riemann sphere and a set of stationary states in the finite-volume Hilbert space of the integrable 2D QFT introduced by V.A. Fateev. Potential applications of this correspondence to the problem of non-perturbative quantization of classically integrable non-linear sigma models are briefly discussed. A detailed account of the results announced in this letter is contained in a separate publication arXiv:1310.4390.

math-ph↗

arXiv2014

Winding vacuum energies in a deformed O(4) sigma model

We consider the problem of calculating the Casimir energies in the winding sectors of Fateev's SS-model, which is an integrable two-parameter deformation of the O(4) non-linear sigma model in two dimensions. This problem lies beyond the scope of all traditional methods of integrable quantum field theory including the thermodynamic Bethe ansatz and non-linear integral equations. Here we propose a solution based on a remarkable correspondence between classical and quantum integrable systems and express the winding energies in terms of certain solutions of the classical sinh-Gordon equation.

hep-th↗

arXiv2014

Integrable structure of Quantum Field Theory: Classical flat connections versus quantum stationary states

We establish a correspondence between an infinite set of special solutions of the (classical) modified sinh-Gordon equation and a set of stationary states in the finite-volume Hilbert space of the integrable 2D QFT invented by V.A. Fateev. The modified sinh-Gordon equation arise in this case as a zero-curvature condition for a class of multivalued connections of the punctured Riemann sphere, similarly to Hitchin's self-duality equations. The proposed correspondence between the classical and quantum integrable systems provides a powerful tool for deriving functional and integral equations which determine the full spectrum of local integrals of motion for massive QFT in a finite volume. Potential applications of our results to the problem of non-perturbative quantization of classically integrable non-linear sigma models are briefly discussed.

hep-th↗

arXiv2013

ODE/IM correspondence for the Fateev model

The Fateev model is somewhat special among two-dimensional quantum field theories. For different values of the parameters,it can be reduced to a variety of integrable systems. An incomplete list of the reductions includes O(3) and O(4) non-linear sigma models and their continuous deformations (2D and 3D sausages, anisotropic principal chiral field), the Bukhvostov-Lipatov model, the N=2 supersymmetric sine-Gordon model, as well as the integrable perturbed SU_2(n)\otimes SU_2(p-2)/SU_2(n+p-2) coset CFT. The model possesses a mysterious symmetry structure of the exceptional quantum superalgebras U_q{\hat{\big(D(2|1;α)}}\big). In this work, we propose the ODE/IM correspondence between the Fateev model and a certain generalization of the classical problem of constant mean curvature embedding of a thrice-punctured sphere in AdS_3.

hep-th↗

arXiv2012

Integrable boundary interaction in 3D target space: the "pillow-brane" model

We propose a model of boundary interaction, with three-dimensional target space, and the boundary values of the field {\vec X}\in R^3 constrained to lay on a two-dimensional surface of the "pillow" shape. We argue that the model is integrable, and suggest that its exact solution is described in terms of certain linear ordinary differential equation.

hep-th↗

arXiv2007

Resistively shunted Josephson junctions: QFT predictions versus MC results

During the last fourteen years several exact results were obtained for the so-called boundary sine-Gordon model. In the case of a conformal bulk this 2D boundary quantum field theory describes the universal scaling behavior of the Caldeira-Leggett model of resistively shunted Josephson junctions. In this work, we use a recently developed Monte Carlo technique to test some of the analytical predictions.

cond-mat.other↗

arXiv2006

Universal scaling behavior of the single electron box in the strong tunneling limit

We perform a numerical analysis of recently proposed scaling functions for the single electron box. Specifically, we study the ``magnetic'' susceptibility as a function of tunneling conductance and gate charge, and the effective charging energy at zero gate charge as a function of tunneling conductance in the strong tunneling limit. Our Monte Carlo results confirm the accuracy of the theoretical predictions.

cond-mat.mes-hall↗

arXiv2005

Boundary RG Flow Associated with the AKNS Soliton Hierarchy

We introduce and study an integrable boundary flow possessing an infinite number of conserving charges which can be thought of as quantum counterparts of the Ablowitz, Kaup, Newell and Segur Hamiltonians. We propose an exact expression for overlap amplitudes of the boundary state with all primary states in terms of solutions of certain ordinary linear differential equation. The boundary flow is terminated at a nontrivial infrared fixed point. We identify a form of whole boundary state corresponding to this fixed point.

hep-th↗