—个新的m×m矩阵Kaup-Newell谱问题及其相应的可积分解(英文)

A new m×m matrix Kaup-Newell spectral problem is constructed from a normal 2×2 matrix Kaup-Newell spectral problem,a new integrable decomposition of the Kaup-NeweU equation is presented.Through this process,we find the structure of the r-matrix is interesting.     

一个新的m×m矩阵Kaup-Newell谱问题及其相应的可积分解

A new m × m matrix Kaup-Newell spectral problem is constructed from a normal 2 × 2 matrix Kaup-Newell spectral problem, a new integrable decomposition of the Kaup-Newell equation is presented. Through this process, we find the structure of the r-matrix is interesting.     

ADJOINT SYMMETRY CONSTRAINTS OF MULTICOMPONENT AKNS EQUATIONS

A soliton hierarchy of multicomponent AKNS equations is generated from an arbitraryorder matrix spectral problem,along with its bi-Hamiltonian formulation.Adjoint symmetryconstraints are presented to manipulate binary nonlinearization for the associated arbitraryorder matrix spectral problem.The resulting spatial and temporal constrained fiows are shownto provide integrable decompositions of the multicomponent AKNS equations.     

TWO CLASSES OF INTEGRABLE COUPLING FOR AKNS HIERARCHY

A set of new matrix Lie algebra is constructed, which is devoted to obtaining a new loop algebra A 2M . Then we use the idea of enlarging spectral problems to make an enlarged spectral problems. It follows that the multi-component AKNS hierarchy is presented. Further, two classes of integrable coupling of the AKNS hierarchy are obtained by enlarging spectral problems.     

DARBOUX TRANSFORMATION OF A NONLINEAR EVOLUTION EQUATION AND ITS EXPLICIT SOLUTIONS

In this paper, we study a differential-difference equation associated with discrete 3 × 3 matrix spectral problem. Based on gauge transformation of the spectral problm, Darboux transformation of the differential-difference equation is given. In order to solve the differential-difference equation, a systematic algebraic algorithm is given. As an application, explicit soliton solutions of the differential-difference equation are given.     

约束的NLS系统的刚体型Poisson结构

A constrained system associated with a 3×3 matrix spectral problem of the nonlinear Schrodinger(NLS) hierarchy is proposed. It is shown that the constrained system is a Hamiltonian system with the rigid body type Poisson structure on the Poisson manifold R3N. Further, the reduction of the constrained system extended to the common level set of the complex cones is proved to be the constrained AKNS system on C2N.     

A NEW DISCRETE INTEGRABLE COUPLING SYSTEM AND ITS HAMILTONIAN STRUCTURE FOR THE MODIFIED TODA LATTICE HIERARCHY

We present a new discrete integrable coupling system by using the matrix Lax pair U, V ∈ sl(4). A novel spectral problem of modified Toda lattice soliton hierarchy is considered. Then, a new discrete integrable coupling equation hierarchy is obtained through the method of the enlarged Lax pair. Finally, we obtain the Hamiltonian structure of the integrable coupling system of the soliton equation hierarchy using the matrix-form trace identity. This discrete integrable coupling system includes a kind of a modified Toda lattice hierarchy.     

THE COMPACT ALGEBRA STRUCTURE OF SOLITON EQUATIONS, THEIR SPINOR AKNS SYSTEM AND REALIZATION ON SPHERE

It is shown that a great sort of soliton equations, such as sine-Grodon equation and others whose inverse scattering problem is described by the AKNS system, has both noncompact and compact algebra structures on the same footing. The spinor AKNS system and realization on sphere with respect to the compact structure of the soliton equations are given.     

On the Transformations of the Potentials, Integrable Evolution Equations and Backhand Transformations

The generalization of the AKNS method, Calogero method and Konopelchenko method is given in three respects. First, the new fundamental relations associated with the matrix spectral problem and a new explicit expression related to the matrixes В and G which are contained in the transformations of the transition matrixes are obtained. Then the wide classes of the integrable evolution equations are conveniently derived without improperly assuming B=C. Finally, an important property of the operator LA is showed, the conditions connected with the temporal half of the Baeklund transformations and the new simple expressions of the integrals of motion are deduced.     

AN INTEGRABLE COUPLING OF THE GENERALIZED AKNS HIERARCHY

A direct method for establishing integrable couplings is proposed in this paper by constructing a new loop algebra G. As an illustration by example, an integrable coupling of the generalized AKNS hierarchy is given. Furthermore, as a reduction of the generalized AKNS hierarchy, an integrable coupling of the well-known G J hierarchy is presented. Again a simple example for the integrable coupling of the MKdV equation is also given. This method can be used generally.     

Binary Nonlinearization of the Nonlinear Schr?dinger Equation Under an Implicit Symmetry Constraint

By modifying the procedure of binary nonlinearization for the AKNS spectral problem and its adjoint spectral problem under an implicit symmetry constraint,we obtain a finite dimensional system from the Lax pair of the nonlinear Schr¨odinger equation.We show that this system is a completely integrable Hamiltonian system.     

Long-time asymptotics for the initial-boundary value problem of coupled Hirota equation on the half-line

The object of this work is to investigate the initial-boundary value problem for coupled Hirota equation on the half-line.We show that the solution of the coupled Hirota equation can be expressed in terms of the solution of a 3×3 matrix Riemann-Hilbert problem formulated in the complex k-plane.The relevant jump matrices are explicitly given in terms of the matrix-valued spectral functions s(k)and S(k)that depend on the initial data and boundary values,respectively.Then,applying nonlinear steepest descent techniques to the associated 3×3 matrix-valued Riemann-Hilbert problem,we can give the precise leading-order asymptotic formulas and uniform error estimates for the solution of the coupled Hirota equation.     

MATRIX EQUATION AXB = E WITH PX = sXP CONSTRAINT

The matrix equation AXB = E with the constraint PX=sXP is considered,where P is a given Hermitian matrix satisfying p~2=I and s=±1.By an eigenvalue decomposition of P,the constrained problem can be equivalently transformed to a well-known unconstrained problem of matrix equation whose coefficient matrices contain the corresponding eigenvector, and hence the constrained problem can be solved in terms of the eigenvectors of P.A simple and eigenvector-free formula of the general solutions to the constrained problem by generalized inverses of the coefficient matrices A and B is presented.Moreover,a similar problem of the matrix equation with generalized constraint is discussed.     

Determinant representation of Darboux transformation for the AKNS system

The n-fold Darboux transform (DT) is a 2×2 matrix for the Ablowitz-Kaup-Newell-Segur (AKNS) system. In this paper, each element of this matrix is expressed by 2n 1 ranks' determinants. Using these formulae, the determinant expressions of eigenfunctions generated by the n-fold DT are obtained. Furthermore, we give out the explicit forms of the n-soliton surface of the Nonlinear Schrodinger Equation (NLS) by the determinant of eigenfunctions.     

THE SASA-SATSUMA EQUATION ON A NON-ZERO BACKGROUND: THE INVERSE SCATTERING TRANSFORM AND MULTI-SOLITON SOLUTIONS

We concentrate on the inverse scattering transformation for the Sasa-Satsuma equation with 3×3 matrix spectrum problem and a nonzero boundary condition. To circumvent the multi-value of eigenvalues, we introduce a suitable two-sheet Riemann surface to map the original spectral parameter k into a single-valued parameter z. The analyticity of the Jost eigenfunctions and scattering coefficients of the Lax pair for the Sasa-Satsuma equation are analyzed in detail. According to the analyticity of the...     

Multivariate refinement equation with nonnegative masks

This paper is concerned with multivariate refinement equations of the type where (?) is the unknown function defined on the s-dimensional Euclidean space Rs, a is a finitely supported nonnegative sequence on Zs, and M is an s×s dilation matrix with m := |detM|. We characterize the existence of L2-solution of refinement equation in terms of spectral radius of a certain finite matrix or transition operator associated with refinement mask a and dilation matrix M. For s = 1 and M = 2, the sufficient and necessary conditions are obtained to characterize the existence of continuous solution of this refinement equation.     

Finite difference method and its convergent error analyses for thermistor problem

The thermistor problem is an initial-boundary value problem of coupled nonlinear differential equations. The nonlinear PDEs consist of a heat equation with the Joule heating as asource and a current conservation equation with temperature-dopendent electrical conductivity.This problem has important opplicatioJls in industry. In this paper, A new finite differencescheme is proposed on nonuniform rectangular partition for the thermistor problem. In the theo-retical analyses,the second-order error estimates are obtained for electrical potential in discrete L^2 and H^1 norms,and for the temperature in L^2 norm. In order to get these second-order errorestimates,the Joule heating source is used in a changed equivalent form.     

A new computational approach for solving optimal control of linear PDEs problem

In this paper, we present a new computational approach for solving an internal optimal control problem, which is governed by a linear parabolic partial differential equation. Our approach is to approximate the PDE problem by a nonhomogeneous ordinary differential equation system in higher dimension. Then, the homogeneous part of ODES is solved using semigroup theory. In the next step, the convergence of this approach is verified by means of Toeplitz matrix. In the rest of the paper, the optimal control problem is solved by utilizing the solution of homogeneous part. Finally, a numerical example is given.     

A NEW PRECONDITIONING STRATEGY FOR SOLVING A CLASS OF TIME-DEPENDENT PDE-CONSTRAINED OPTIMIZATION PROBLEMS

In this paper, by exploiting the special block and sparse structure of the coefficient matrix, we present a new preconditioning strategy for solving large sparse linear systems arising in the time-dependent distributed control problem involving the heat equation with two different functions. First a natural order-reduction is performed, and then the reduced- order linear system of equations is solved by the preconditioned MINRES algorithm with a new preconditioning techniques. The spectral properties of the preconditioned matrix are analyzed. Numerical results demonstrate that the preconditioning strategy for solving the large sparse systems discretized from the time-dependent problems is more effective for a wide range of mesh sizes and the value of the regularization parameter.     

On the Matrix Equation A~2=J

An unsolved problem is to enumerate all solutions for the matrix equation A~2=Jwhere A is an n×n (0.1)-matrix and J is the n×n matr trix with every entry being 1. Here we present a family of n×n generalized circulant (0.1)-matrices each of whose square is J. Moreover. the existence of this family is unique up to permutational similarity.