The Zero Curvature Form of Integrable Hierarchies in the ℤ × ℤ-Matrices

2012 ◽  
Vol 19 (02) ◽  
pp. 237-262
Author(s):  
G. F. Helminck ◽  
A. V. Opimakh
Keyword(s):  
Lie Algebra ◽  
Integrable Hierarchies ◽  
Evolution Equations ◽  
Integrable Hierarchy ◽  
Connection Form ◽  
Minimal Realization ◽  
Band Matrices ◽  
Zero Curvature ◽  
Lax Equations ◽  
Finite Band

In this paper it is shown how one can associate to a finite number of commuting directions in the Lie algebra of upper triangular ℤ × ℤ-matrices an integrable hierarchy consisting of a set of evolution equations for perturbations of the basic directions inside the mentioned Lie algebra. They amount to a tower of differential and difference equations for the coefficients of these perturbed matrices. The equations of the hierarchy are conveniently formulated in so-called Lax equations for these perturbations. They possess a minimal realization for which it is shown that the relevant evolutions of the perturbation commute. These Lax equations are shown in a purely algebraic way to be equivalent with zero curvature equations for a collection of finite band matrices, that are the components of a formal connection form. One concludes with the linearization of the hierarchies and the notion of wave matrices at zero, which is the algebraic substitute for a basis of the horizontal sections of the formal connection corresponding to this connection form.

On Generating Integrable Dynamical Systems in 1+1 and 2+1 Dimensions by Using Semisimple Lie Algebras

2015 ◽  
Vol 70 (11) ◽  
pp. 975-977 ◽  
Author(s):  
Yufeng Zhang ◽  
Honwah Tam ◽  
Lixin Wu
Keyword(s):  
Lie Algebra ◽  
Evolution Equations ◽  
Mkdv Equation ◽  
Integrable Hierarchy ◽  
Nls Equation ◽  
Soliton Equation ◽  
Integrable Equations ◽  
Zero Curvature ◽  
Integrable Dynamical Systems ◽  
Representation Method

AbstractWe deduce a set of integrable equations under the framework of zero curvature equations and obtain two sets of integrable soliton equations, which can be reduced to some new integrable equations including the generalised nonlinear Schrödinger (NLS) equation. Under the case where the isospectral functions are one-order polynomials in the parameter λ, we generate a set of rational integrable equations, which are reduced to the loop soliton equation. Under the case where the derivative λt of the spectral parameter λ is a quadratic algebraic curve in λ, we derive a set of variable-coefficient integrable equations. In addition, we discretise a pair of isospectral problems introduced through the Lie algebra given by us for which a set of new semi-discrete nonlinear equations are available; furthermore, the semi-discrete MKdV equation and the Hirota lattice equation are followed to produce, respectively. Finally, we apply the Lie algebra to introduce a set of operator Lax pairs with an operator, and then through the Tu scheme and the binomial-residue representation method proposed by us, we generate a 2+1-dimensional integrable hierarchy of evolution equations, which reduces to a generalised 2+1-dimensional Davey-Stewartson (DS) equation.

scholarly journals The Strict AKNS Hierarchy: Its Structure and Solutions

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
G. F. Helminck
Keyword(s):  
Commutative Algebra ◽  
Loop Space ◽  
Integrable Hierarchy ◽  
Akns Hierarchy ◽  
Zero Curvature ◽  
Lax Equations

We discuss an integrable hierarchy of compatible Lax equations that is obtained by a wider deformation of a commutative algebra in the loop space ofsl2than that in the AKNS case and whose Lax equations are based on a different decomposition of this loop space. We show the compatibility of these Lax equations and that they are equivalent to a set of zero curvature relations. We present a linearization of the system and conclude by giving a wide construction of solutions of this hierarchy.

INTEGRABLE HIERARCHIES FROM BRST COHOMOLOGY

2005 ◽  
Vol 20 (01) ◽  
pp. 51-59
Author(s):  
V. CALIAN ◽  
G. STOENESCU
Keyword(s):  
Field Theory ◽  
Hamiltonian System ◽  
Hamiltonian Structure ◽  
Integrable Hierarchies ◽  
Evolution Equations ◽  
Classical Field Theory ◽  
Classical Field ◽  
Integrable Hierarchy ◽  
Brst Cohomology ◽  
Gauge Fixing

We demonstrate that the Hamiltonian structure and the integrability of a system of evolution equations can be formulated in terms of a classical field theory using BRST and anti-BRST symmetries. We derive the field theory action and explicitly generate the integrable hierarchy associated to a bi-Hamiltonian system based on cohomological arguments and gauge-fixing deformations.

SUPER INTEGRABLE HIERARCHY AND SUPER HAMILTONIAN STRUCTURES ASSOCIATED WITH GUO HIERARCHY

2009 ◽  
Vol 23 (29) ◽  
pp. 3491-3496 ◽  
Author(s):  
NING ZHANG ◽  
HUANHE DONG
Keyword(s):  
Integrable Hierarchies ◽  
Lie Superalgebra ◽  
Integrable Hierarchy ◽  
Hamiltonian Structures ◽  
Curvature Equation ◽  
Zero Curvature

A Lie superalgebra is constructed from which establishes an isospectral problems. By solving the zero curvature equation, a resulting super hierarchies of the Guo hierarchy are obtained. By making use of the super identity, the Hamiltonian structures of the above super integrable hierarchies are generated, this method can be used to other superhierarchy.

scholarly journals Generating of Nonisospectral Integrable Hierarchies via the Lie-Algebraic Recursion Scheme

Mathematics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 621
Author(s):  
Haifeng Wang ◽  
Yufeng Zhang
Keyword(s):  
Lie Algebra ◽  
Efficient Method ◽  
Integrable Hierarchies ◽  
Loop Algebra ◽  
Integrable Hierarchy ◽  
Conserved Quantities ◽  
Recursion Scheme

In the paper, we introduce an efficient method for generating non-isospectral integrable hierarchies, which can be used to derive a great many non-isospectral integrable hierarchies. Based on the scheme, we derive a non-isospectral integrable hierarchy by using Lie algebra and the corresponding loop algebra. It follows that some symmetries of the non-isospectral integrable hierarchy are also studied. Additionally, we also obtain a few conserved quantities of the isospectral integrable hierarchies.

scholarly journals Two Isospectral-Nonisospectral Super-Integrable Hierarchies and Related Invariant Solutions

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1797
Author(s):  
Huanhuan Lu ◽  
Yufeng Zhang
Keyword(s):  
Integrable Hierarchies ◽  
Integrable Hierarchy ◽  
Lie Point Symmetries ◽  
Invariant Solutions ◽  
Group Invariant ◽  
Loop Algebras ◽  
Zero Curvature ◽  
Group Invariant Solutions ◽  
Fokker Plank Equation ◽  
Coupled Equation

In this article, we adopt two kinds of loop algebras corresponding to the Lie algebra B(0,1) to introduce two line spectral problems with different numbers of even and odd superfunctions. Through generalizing the time evolution λt to a polynomial of λ, two isospectral-nonisospectral super integrable hierarchies are derived in terms of Tu scheme and zero-curvature equation. Among them, the first super integrable hierarchy is further reduced to generalized Fokker–Plank equation and special bond pricing equation, as well as an explicit super integrable system under the choice of specific parameters. More specifically, a super integrable coupled equation is derived and the corresponding integrable properties are discussed, including the Lie point symmetries and one-parameter Lie symmetry groups as well as group-invariant solutions associated with characteristic equation.

scholarly journals A New Approach for Generating the TX Hierarchy as well as Its Integrable Couplings

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Guangming Wang
Keyword(s):  
Hamiltonian Structure ◽  
Evolution Equations ◽  
Loop Algebra ◽  
Integrable Hierarchy ◽  
New Approach ◽  
Zero Curvature ◽  
Integrable Couplings ◽  
Isospectral Problem ◽  
Integrable Coupling

Tu Guizhang and Xu Baozhi once introduced an isospectral problem by a loop algebra with degree beingλ, for which an integrable hierarchy of evolution equations (called the TX hierarchy) was derived under the frame of zero curvature equations. In the paper, we present a loop algebra whose degrees are2λand2λ+1to simply represent the above isospectral matrix and easily derive the TX hierarchy. Specially, through enlarging the loop algebra with 3 dimensions to 6 dimensions, we generate a new integrable coupling of the TX hierarchy and its corresponding Hamiltonian structure.

scholarly journals Bi-Integrable Couplings of a New Soliton Hierarchy Associated withSO(4)

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yan Cao ◽  
Liangyun Chen ◽  
Baiying He
Keyword(s):  
Lie Algebra ◽  
Integrable Hierarchy ◽  
Hamiltonian Structures ◽  
Spectral Problems ◽  
Zero Curvature ◽  
Soliton Hierarchy ◽  
Integrable Couplings ◽  
Orthogonal Lie Algebra ◽  
Isospectral Problem

Based on the six-dimensional real special orthogonal Lie algebraSO(4), a new Lax integrable hierarchy is obtained by constructing an isospectral problem. Furthermore, we construct bi-integrable couplings for this hierarchy from the enlarged matrix spectral problems and the enlarged zero curvature equations. Hamiltonian structures of the obtained bi-integrable couplings are constructed by the variational identity.

scholarly journals INTEGRABLE HIERARCHIES AND CONTACT TERMS IN u-PLANE INTEGRALS OF TOPOLOGICALLY TWISTED SUPERSYMMETRIC GAUGE THEORIES

1999 ◽  
Vol 14 (07) ◽  
pp. 1001-1013 ◽  
Author(s):  
KANEHISA TAKASAKI
Keyword(s):  
Integrable Hierarchies ◽  
Gauge Theories ◽  
Point Of View ◽  
Coupling Constants ◽  
Integrable Hierarchy ◽  
Supersymmetric Gauge Theories ◽  
Tau Function ◽  
Single Time ◽  
Whitham Equations ◽  
Supersymmetric Gauge

The u-plane integrals of topologically twisted N=2 supersymmetric gauge theories generally contain contact terms of nonlocal topological observables. This paper proposes an interpretation of these contact terms from the point of view of integrable hierarchies and their Whitham deformations. This is inspired by Mariño and Moore's remark that the blowup formula of the u-plane integral contains a piece that can be interpreted as a single-time tau function of an integrable hierarchy. This single-time tau function can be extended to a multitime version without spoiling the modular invariance of the blowup formula. The multitime tau function is comprised of a Gaussian factor eQ(t1,t2,…) and a theta function. The time variables tn play the role of physical coupling constants of two-observables In(B) carried by the exceptional divisor B. The coefficients qmn of the Gaussian part are identified to be the contact terms of these two-observables. This identification is further examined in the language of Whitham equations. All relevant quantities are written in the form of derivatives of the prepotential.

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