arXiv subjects

I. T. Habibullin

Publications and source records attributed to I. T. Habibullin.

27 records · Page 2Linked to original sources

arXiv2016

On a method for constructing the Lax pairs for nonlinear integrable equations

We suggest a direct algorithm for searching the Lax pairs for nonlinear integrable equations. It is effective for both continuous and discrete models. The first operator of the Lax pair corresponding to a given nonlinear equation is found immediately, coinciding with the linearization of the considered nonlinear equation. The second one is obtained as an invariant manifold to the linearized equation. A surprisingly simple relation between the second operator of the Lax pair and the recursion operator is discussed: the recursion operator can immediately be found from the Lax pair. Examples considered in the article are convincing evidence that the found Lax pairs differ from the classical ones. The examples also show that the suggested objects are true Lax pairs which allow the construction of infinite series of conservation laws and hierarchies of higher symmetries. In the case of the hyperbolic type partial differential equation our algorithm is slightly modified; in order to construct the Lax pairs from the invariant manifolds we use the cutting off conditions for the corresponding infinite Laplace sequence. The efficiency of the method is illustrated by application to some equations given in the Svinolupov-Sokolov classification list for which the Lax pairs and the recursion operators have not been found earlier.

nlin.SI↗

arXiv2015

Asymptotic diagonalization of the Discrete Lax pair around singularities and conservation laws for dynamical systems

A method of the formal diagonalization of the discrete linear operator with a parameter is studied. In the case when the operator provides a Lax operator for a nonlinear quad system the formal diagonalization method allows one to describe effectively conservation laws and generalized symmetries for this system. Asymptotic representation of the Lax operators eigenfunctions are constructed and infinite series of conservation laws are described for the quad system connected with $A^{(1)}_3$ affine Lie algebra, for the modified discrete Boussinesq system and for the discrete Tzitzeica equation. For a newly found multiquadratic discrete model conservation laws and several generalized symmetries are presented.

nlin.SI↗

arXiv2012

Integrable initial boundary value problems

The problem of searching boundary value problems for soliton equations consistent with the integrability property is discussed. A method of describing integrals of motion for the integrable initial boundary value problems for the Kadomtsev-Petviashvili equation is suggested via Green identity.

nlin.SI↗

arXiv2004

Multidimensional integrable boundary problems

A method of looking for boundary conditions consistent with the integrability property of multidimensional Kadomtsev-Petviashvili (KP) type equations is discussed. The method is based on involutions of the Lax pair taken at the border plane. New classes of boundary conditions for the KP and Hirota equations are proposed consistent with the Lax pair. The boundary problem on the stripe 0<y<1 for the KP equation is discussed, its exact solutions are found. Ward's problem on discrete versions of the generalized Toda chains is briefly discussed.

nlin.SI↗

arXiv1999

The KdV equation on a half-line

The initial boundary value problem on a half-line for the KdV equation with the boundary conditions $u|_{x=0}=a\leq0$, $u_{xx}|_{x=0}=3a^2$ is integrated by means of the inverse scattering method. In order to find the time evolution of the scattering matrix it turned out to be sufficient to solve the Riemann problem on a hyperelliptic curve of genus two, where the conjugation matrices are effectively defined by initial data.

solv-int↗

arXiv1998

Integrable boundary conditions for nonlinear lattices

Integrable boundary conditions in 1+1 and 2+1 dimensions are discussed from the higher symmetries point of view. Boundary conditions consistent with the discrete Landau-Lifshitz model and infinite 2D Toda lattice are represented.

solv-int↗

arXiv1998

Initial boundary value problem on a half-line for the MKdV equation

Initial boundary value problem on a half-line for the Modified KdV equation is considered with the boundary conditions equal to zero at the origin and initial condition chosen arbitrary decreasing rapidly enough and this problem is plunged into the scheme of the inverse scattering method. Here the inverse scattering problem is reduced to the Riemann problem on a system of rays on the complex plane.

solv-int↗

arXiv1995

Symmetry approach in boundary value problems

The problem of construction of the boundary conditions for nonlinear equations is considered compatible with their higher symmetries. Boundary conditions for the sine-Gordon, Jiber-Shabat and KdV equations are discussed. New examples are found for the Jiber-Shabat equation.

solv-int↗

arXiv1995

Integrable boundary conditions for the Toda lattice

The problem of construction of the boundary conditions for the Toda lattice compatible with its higher symmetries is considered. It is demonstrated that this problem is reduced to finding of the differential constraints consistent with the ZS-AKNS hierarchy. A method of their construction is offered based on the Bäcklund transformations. It is shown that the generalized Toda lattices corresponding to the non-exceptional Lie algebras of finite growth can be obtained by imposing one of the four simplest integrable boundary conditions on the both ends of the lattice. This fact allows, in particular, to solve the problem of reduction of the series $A$ Toda lattices into the series $D$ ones. Deformations of the found boundary conditions are presented which leads to the Painlevé type equations. Key words: Toda lattice, boundary conditions, integrability, Bäcklund transformation, Lie algebras, Painlevé equations

solv-int↗