TD孤子方程族的可积耦合及其哈密顿结构

用拓展谱问题方法构造TD族的可积耦合,并应用二次型恒等式寻求拓展的TD族哈密顿结构.     

Integrable decomposition of a hierarchy of soliton equations and integrable coupling system by semidirect sums of Lie algebras

Staring from a new spectral problem, a hierarchy of the soliton equations is derived. It is shown that the associated hierarchies are infinite-dimensional integrable Hamiltonian systems. By the procedure of nonlinearization of the Lax pairs, the integrable decomposition of the whole soliton hierarchy is given. Further, we construct two integrable coupling systems for the hierarchy by the conception of semidirect sums of Lie algebras.     

Hamiltonian and super-Hamiltonian systems of a hierarchy of soliton equations

By considering an isospectral eigenvalue problem, a hierarchy of soliton equations are derived. Two types of extensions are presented by enlarging the associated spectral problem. With the aid of generalized trace identity and the super-trace identity, the Hamiltonian and super-Hamiltonian structures for the integrable extensions are established.     

The integrability and parametric representation of a hierarchy of soliton equations

In this paper after having obtained the Lax pair of a hierarchy of soliton equations,we discuss the parametric representation for finite-band solutions of the stationary solitonequation, and prove it can be represented as a Hamiltonian system which is integrable inLiouville sense. The nonconfocal involutive integral representations {Fm} are obtained also.In the condition of finite-band solutions of the soliton equation, the time and space can bedevided inio two Hamiltonian systems, so the fi…     

Fermionic approach to soliton equations

In this paper we exploit the algebraic structure of the soliton equations and find solutions in terms of fermion particles. We show how determinants arise naturally in the fermionic approach to soliton equations. We write the τ-function for charged free fermions in terms of determinants. Examples of how to get soliton, rational and dromion solutions from τ-functions for the various soliton equations are given.     

Integrable couplings,bi‐integrable couplings and their Hamiltonian structures of the Giachetti–Johnson soliton hierarchy

On the basis of zero curvature equations from semi‐direct sums of Lie algebras, we construct integrable couplings of the Giachetti–Johnson hierarchy of soliton equations. We also establish Hamiltonian structures of the resulting integrable couplings by the variational identity. Moreover, we obtain bi‐integrable couplings of the Giachetti–Johnson hierarchy and their Hamiltonian structures by applying a class of non‐semisimple matrix loop algebras consisting of triangular block matrices. Copyright © 2014 John Wiley & Sons, Ltd.     

New exact solutions to breaking soliton equations and Whitham-Broer-Kaup equations

In this paper, by using the improved Riccati equations method, we obtain several types of exact traveling wave solutions of breaking soliton equations and Whitham-Broer-Kaup equations. These explicit exact solutions contain solitary wave solutions, periodic wave solutions and the combined formal solitary wave solutions. The method employed here can also be applied to solve more nonlinear evolution equations.     

Factorization of a hierarchy of the lattice soliton equations from a binary Bargmann symmetry constraint

Staring from a discrete spectral problem, a hierarchy of the lattice soliton equations is derived. It is shown that each lattice equation in resulting hierarchy is Liouville integrable discrete Hamiltonian system. The binary nonlinearization of the Lax pairs and the adjoint Lax pairs of the resulting hierarchy is discussed. Each lattice soliton equation in the resulting hierarchy can be factored by an integrable symplectic map and a finite-dimensional integrable system in Liouville sense. Especially, factorization of a discrete Kdv equation is given.     

Integrable superconductivity and Richardson equations

For the integrable generalized model of superconductivity, the solution of the Richardson equations is studied for a model spectrum. For the case of a narrow band, the solution is presented in terms of generalized Laguerre or Jacobi polynomials. In the asymptotic limit, when the Richardson equations are transformed into a singular integral equation, the properties of the integration contour are discussed and the spectral density is calculated. The conditions of appearance of gaps in the spectrum are investigated. Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 59, No. 3, pp. 314–326, March, 2007.     

Geometry and multidimensional soliton equations

The connection between the differential geometry of curves and (2+1)-dimensional integrable systems is established. The Zakharov equation, the modified Veselov-Novikov equation, the modified Kortewegde Vries equation, etc., are equivalent in the Lakshmanan sense to (2+1)-dimensional spin systems. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 118, No. 3, pp. 441–451, March, 1999.     

A new integrable generalized Neumann system related to soliton hierarchy

In the present paper, the nonlinearization approach is applied to the soliton hierarchy associated with 3 × 3 matrix spectral problems. A new finite-dimensional integrable generalized C. Neumann system is obtained. The involutive system of conserved integrals is constructed by a direct method. Moreover the involutive solution of the soliton hierarchy is also given.     

Asymptotic solutions of singularly perturbed second-order differential equations and application to multi-point boundary value problems

In this work, a singularly perturbed second-order ordinary differential equation is solved by applying a new Liouville–Green transform and the asymptotic solutions are obtained. As an application, we employ our results in discussing a second-order multi-point boundary value problem.     

Intertwining operators and soliton equations

The fermionic approach to the Kadomtsev-Petviashvili hierarchy, suggested by the Kyoto school (Sato, Date, Jimbo, Kashiwara, and Miwa) in 1981–4, is generalized on the basis of the idea that, in a sense, the components of intertwining operators are a generalization of free fermions forgl _∞. Integrable hierarchies related to symmetries of Kac-Moody algebras are described in terms of intertwining operators. The bosonization of these operators for various choices of the Heisenberg subalgebra is explicity written out. These various realizations result in distinct hierarchies of soliton equations. For example, forsl _N -symmetries this gives the hierarchies obtained by the (n ₁,...,n _s )-reduction from thes-component KP hierarchy introduced by Kac and van de Leur. The research of both authors was supported in part by RFBR grant No. 96-02-18046, grant No. 96-15-96455 for the support of leading scientific schools, and RFBR-CNRS grant No. 98-01-22033. International Center for Nonlinear Science at the Landau Institute of Theoretical Physics. Institute of Theoretical and Experimental Physics. Translated from Funktsional’nyi Analiz i Ego Prilozheniya, Vol. 33, No. 4, pp. 1–24, October–December, 1999. Translated by M. I. Golenishcheva-Kutuzova     

Infinitely many solutions to perturbed elliptic equations

A new version of perturbation theory is developed which produces infinitely many sign-changing critical points for uneven functionals. The abstract result is applied to the following elliptic equations with a Hardy potential and a perturbation from symmetry:

     

Pseudo soliton in fluidized beds and its perturbed treatment

The author summarize the recent analysis of a two-fluid model which describes fluidized beds of granular particles. It has been found that near the transition point from stable fluidized beds to unstable ones the two-fluid model is reduced to the KdV equation with small dissipation. The amplitude and the propagating velocity of a pulse of the reduced equation is obtained.Department of Physics, Tohoku University, Sendai 980, Japan. E-mail: hisao@cmpt01.phys.tohoku.ac.jp. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 99, No. 2, pp. 309–314, May, 1994.     

Algebraic geometry and soliton dynamics

Algebro-geometric sectors of solutions of the KP hierarchy are described in terms of τ-functions and vertex operators. Some useful identities involving theta functions and prime forms on Riemann surfaces are provided which are applied to obtain explicit solutions in the bilinear formalism. By using a dressing method for τ-functions the soliton dynamics against the background of quasiperiodic solutions is characterized. Furthermore, a formula for the soliton shifts in terms of prime forms on Riemann surfaces is obtained.