arXiv subjects

A. Marshakov

Publications and source records attributed to A. Marshakov.

At least 55 records · Page 3Linked to original sources

arXiv2004

Strings, Integrable Systems, Geometry and Statistical Models

The role of integrable systems in string theory is discussed. We remind old examples of the correspondence between stringy partition functions or effective actions and integrable equations, based on effective application of the matrix model technique. Then we turn to a new example, coming from the Nekrasov deformation of the Seiberg-Witten prepotential. In the last case the deformed theory is described by a different statistical model, which becomes equivalent to a partition function of a topological string. The full partition function of string theory arises therefore always as a certain "quantization" of its quasiclassical geometry.

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arXiv2004

Integrable Structure of the Dirichlet Boundary Problem in Multiply-Connected Domains

We study the integrable structure of the Dirichlet boundary problem in two dimensions and extend the approach to the case of planar multiply-connected domains. The solution to the Dirichlet boundary problem in multiply-connected case is given through a quasiclassical tau-function, which generalizes the tau-function of the dispersionless Toda hierarchy. It is shown to obey an infinite hierarchy of Hirota-like equations which directly follow from properties of the Dirichlet Green function and from the Fay identities. The relation to multi-support solutions of matrix models is briefly discussed.

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arXiv2003

On the Dirichlet Boundary Problem and Hirota Equations

We review the integrable structure of the Dirichlet boundary problem in two dimensions. The solution to the Dirichlet boundary problem for simply-connected case is given through a quasiclassical tau-function, which satisfies the Hirota equations of the dispersionless Toda hierarchy, following from properties of the Dirichlet Green function. We also outline a possible generalization to the case of multiply-connected domains related to the multi-support solutions of matrix models.

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arXiv2003

DV and WDVV

We prove that the quasiclassical tau-function of the multi-support solutions to matrix models, proposed recently by Dijkgraaf and Vafa to be related to the Cachazo-Intrilligator-Vafa superpotentials of the N=1 supersymmetric Yang-Mills theories, satisfies the Witten-Dijkgraaf-Verlinde-Verlinde equations.

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arXiv2002

String Theory or Field Theory?

The status of string theory is reviewed, and major recent developments - especially those in going beyond perturbation theory in the string theory and quantum field theory frameworks - are discussed. This analysis helps better understand the role and place of string theory in the modern picture of the physical world. Even though quantum field theory describes a wide range of experimental phenomena, it is emphasized that there are some insurmountable problems inherent in it - notably the impossibility to formulate the quantum theory of gravity on its basis - which prevent it from being a fundamental physical theory of the world of microscopic distances. It is this task, the creation of such a theory, which string theory, currently far from completion, is expected to solve. In spite of its somewhat vague current form, string theory has already led to a number of serious results and greatly contributed to progress in the understanding of quantum field theory. It is these developments which are our concern in this review.

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arXiv2002

Non-Abelian Confinement via Abelian Flux Tubes in Softly Broken N=2 SUSY QCD

We study confinement in softly broken N=2 SUSY QCD with gauge group SU(N_c) and N_f hypermultiplets of fundamental matter (quarks) when the Coulomb branch is lifted by small mass of adjoint matter. Concentrating mostly on the theory with SU(3) gauge group we discuss the N=1 vacua which arise in the weak coupling at large values of quark masses and study flux tubes and monopole confinement in these vacua. In particular we find the BPS strings in SU(3) gauge theory formed by two interacting U(1) gauge fields and two scalar fields generalizing ordinary Abrikosov-Nielsen-Olesen vortices. Then we focus on the SU(3) gauge theories with N_f=4 and N_f=5 flavors with equal masses. In these theories there are N=1 vacua with restored SU(2) gauge subgroup in quantum theory since SU(2) subsectors are not asymptotically free. We show that although the confinement in these theories is due to Abelian flux tubes the multiplicity of meson spectrum is the same as expected in a theory with non-Abelian confinement.

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arXiv2002

On Associativity Equations

We consider the associativity or Witten-Dijkgraaf-Verlinde-Verlinde (WDVV) equations and discuss one of the most relevant for non-perturbative physics class of their solutions based on existence of the residue formulas. It is demonstrated for this case that the proof of associativity equations is reduced to the problem of solving system of algebraic linear equations. The particular examples of solutions related to Landau-Ginzburg topological theories, Seiberg-Witten theories and tau-functions of quasiclassical hierarchies are discussed in detail. We also discuss related questions including covariance of associativity equations, their relation to dispersionless Hirota relations and auxiliary linear problem for the WDVV equations.

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arXiv2001

Integrable Structure of the Dirichlet Boundary Problem in Two Dimensions

We study how the solution of the two-dimensional Dirichlet boundary problem for smooth simply connected domains depends upon variations of the data of the problem. We show that the Hadamard formula for the variation of the Dirichlet Green function under deformations of the domain reveals an integrable structure. The independent variables corresponding to the infinite set of commuting flows are identified with harmonic moments of the domain. The solution to the Dirichlet boundary problem is expressed through the tau-function of the dispersionless Toda hierarchy. We also discuss a degenerate case of the Dirichlet problem on the plane with a gap. In this case the tau-function is identical to the partition function of the planar large $N$ limit of the Hermitean one-matrix model.

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arXiv2001

Associativity Equations in Effective SUSY Quantum Field Theories

The role of associativity or WDVV equations in effective supersymmetric quantum theories is discussed and it is demonstrated that for wide class of their solutions when residue formulas are valid the proof of associativity equations can be reduced to solving the system of ordinary linear equations and depends only upon corresponding matching and nondegeneracy conditions. The covariance of WDVV equations upon generic duality transformations and the role of associativity equations in general context of quasiclassical integrable systems is also discussed.

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arXiv2001

Electric-Magnetic Duality and WDVV Equations

We consider the associativity (or WDVV) equations in the form they appear in Seiberg-Witten theory and prove that they are covariant under generic electric-magnetic duality transformations. We discuss the consequences of this covariance from various perspectives.

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arXiv2001

On Associativity Equations in Dispersionless Integrable Hierarchies

We discuss the origin of the associativity (WDVV) equations in the context of quasiclassical or Whitham hierarchies. The associativity equations are shown to be encoded in the dispersionless limit of the Hirota equations for KP and Toda hierarchies. We show, therefore, that any tau-function of dispersionless KP or Toda hierarchy provides a solution to associativity equations. In general, they depend on infinitely many variables. We also discuss the particular solution to the dispersionless Toda hierarchy that describes conformal mappings and construct a family of new solutions to the WDVV equations depending on finite number of variables.

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arXiv2001

On First-Quantized Fermions in Compact Dimensions

We discuss the path integral representation for the fermionic particles and strings and concentrate at the problems arising when some target-space dimensions are compact. An example of partition function for fermionic particle at finite temperature or with one compact target-space dimension is considered in detail. It is demonstrated that the first-quantized path integral requires, in general, presence of nonvanishing "Wilson loops" and modulo some common problems for real fermions in Grassmannian formulation one can try to reinterpret them in terms of condensates of the world-line fermions. The properties of corresponding path integrals in string theory are also discussed.

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arXiv2000

Singular Phases of Seiberg-Witten Integrable Systems: Weak and Strong Coupling

We consider the singular phases of the smooth finite-gap integrable systems arising in the context of Seiberg-Witten theory. These degenerate limits correspond to the weak and strong coupling regimes of SUSY gauge theories. The spectral curves in such limits acquire simpler forms: in most cases they become rational, and the corresponding expressions for coupling constants and superpotentials can be computed explicitly. We verify that in accordance with the computations from quantum field theory, the weak-coupling limit gives rise to precisely the "trigonometric" family of Calogero-Moser and open Toda models, while the strong-coupling limit corresponds to the solitonic degenerations of the finite-gap solutions. The formulae arising provide some new insights into the corresponding phenomena in SUSY gauge theories. Some open conjectures have been proven.

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arXiv2000

Seiberg-Witten Toda Chains and N=1 SQCD

We consider the Seiberg-Witten Toda chains arising in the context of exact solutions to N=2 SUSY Yang-Mills and their relation to the properties of N=1 SUSY gauge theories. In particular, we discuss their "perturbative" and "solitonic" degenerations and demonstrate some relations of the latter ones to the confining properties of N=1 vacua.

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arXiv1999

Duality in Integrable Systems and Generating Functions for New Hamiltonians

Duality in the integrable systems arising in the context of Seiberg-Witten theory shows that their tau-functions indeed can be seen as generating functions for the mutually Poisson-commuting hamiltonians of the {\em dual} systems. We demonstrate that the $Θ$-function coefficients of their expansion can be expressed entirely in terms of the co-ordinates of the Seiberg-Witten integrable system, being, thus, some set of hamiltonians for a dual system.

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arXiv1999

On Double-Elliptic Integrable Systems. 1. A Duality Argument for the case of SU(2)

We construct a two parameter family of 2-particle Hamiltonians closed under the duality operation of interchanging the (relative) momentum and coordinate. Both coordinate and momentum dependence are elliptic, and the modulus of the momentum torus is a non-trivial function of the coordinate. This model contains as limiting cases the standard Ruijsenaars-Calogero and Toda family of Hamiltonians, which are at most elliptic in the coordinates, but not in the momenta.

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arXiv1999

SUSY gauge theories and Whitham integrable systems from compactification and SUSY breaking

We review the Seiberg-Witten construction of low-energy effective actions and BPS spectra in SUSY gauge theories and its formulation in terms of integrable systems. It is also demonstrated how this formulation naturally appears from the compactified version of the theory with partially broken supersymmetry so that the integrable structures arise from the relation between bare and quantum variables and superpotentials of SUSY gauge theories. The Whitham integrable systems, literally corresponding to the uncompactified theory, are then restored by averaging over fast variables in the decompactification limit.

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arXiv1999

Seiberg-Witten Curves and Integrable Systems

This talk gives an introduction into the subject of Seiberg-Witten curves and their relation to integrable systems. We discuss some motivations and origins of this relation and consider explicit construction of various families of Seiberg-Witten curves in terms of corresponding integrable models.

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