SearcharxivSearch

arXiv · 1311.4334

Study of the family of Nonlinear Schrodinger equations by using the Adler-Kosant-Symes framework and the Tu methodology and their Non-holonomic deformation

Abstract

The objective of this work is to explore the class of equations of the Non-linear Schrodinger type by employing the Adler-Kostant-Symes theorem and the Tu methodology.In the first part of the work, the AKS theory is discussed in detail showing how to obtain the non-linear equations starting from a suitably chosen spectral problem.Equations derived by this method include different members of the NLS family like the NLS, the coupled KdV type NLS, the generalized NLS, the vector NLS, the Derivative NLS, the Chen-Lee-Liu and the Kundu-Eckhaus equations. In the second part of the paper, the steps in the Tu methodology that are used to formulate the hierarchy of non-linear evolution equations starting from a spectral problem, are outlined. The AKNS, Kaup-Newell, and generalized DNLS hierarchies are obtained by using this algorithm. Several reductions of the hierarchies are illustrated. The famous trace identity is then applied to obtain the Hamiltonian structure of these hierarchies and establish their complete integrability. In the last part of the paper, the non-holonomic deformation of the class of integrable systems belonging to the NLS family is studied. Equations examined include the NLS, coupled KdV-type NLS and Derivative NLS (both Kaup-Newell and Chen-Lee-Liu equations). NHD is also applied to the hierarchy of equations in the AKNS system and the KN system obtained through application of the Tu methodology.Finally, we discuss the connection between the two formalisms and indicate the directions of our future endeavour in this area.

Explore related subjects

Keep this discovery

BibTeXRIS

Partha Guha, Indranil Mukherjee. 2014-05-22. Study of the family of Nonlinear Schrodinger equations by using the Adler-Kosant-Symes framework and the Tu methodology and their Non-holonomic deformation. https://arxiv.org/abs/1311.4334

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Rogue-like waves from collision of mKdV solitons

Interactions of two solitary waves with an up and a down orientation in the modified Korteweg-de Vries equation are shown to produce rogue-like waves. For waves that asymptotically vanish, the maximum ratio between the height of the interaction profile and the height of the tallest incoming wave is 2.41 when the waves have approximately equal speeds, and this ratio decreases to 2 when the speed ratio is 1.5. For waves that approach a non-zero constant at infinity, the same ratio reaches a maximum of 2.65 when the speed ratio of the waves is 6.32.

nlin.SI

On B\"acklund transformations preserving the Darboux integrability of hyperbolic equations

This paper deals with two kinds of B\"acklund transformations for scalar hyperbolic partial differential equations. We prove that both these types of transformations map solutions of a Darboux integrable equation into solutions of, generally speaking, another but also Darboux integrable equation. The latter fact can be used to roughly check the completeness of a list of Darboux integrable equations. To illustrate this, we apply the above transformations to several equations from a well-known list of Darboux integrable equations and, as a result, obtain a Darboux integrable equation which is absent in this list, but is already known at present. As a generalization of the last equation, we construct a family of Darboux integrable equations that is parametrized by three arbitrary functions, each of which depends on two arguments. This family is probably new.

nlin.SI

Complex singularities for Burgers' equation with piecewise-continuous initial conditions

There is a body of research devoted to understanding how complex singularities of solutions of nonlinear partial differential equations (pdes) spontaneously emerge at $t=0^+$ and propagate for $t>0$, and how their behaviour affects the solution on the real axis. Despite the importance of the small-time limit in these studies, there is still a lack of understanding of how complex singularities are born at $t=0^+$, including for initial conditions that are not analytic functions of the spatial variable. In this paper, we use Burgers' equation as a prototype nonlinear pde and study the complex-plane singularities for initial conditions that are piecewise smooth. Using matched asymptotic expansions, we show how infinitely many singularities emerge from points of discontinuity in a pattern that can be described using branches of the Lambert-$W$ function. For various initial conditions, we observe how these singularities rearrange themselves to align with the appropriate exactly-described long-time behaviour, including sigmoid-shaped travelling waves, constant-area (triangular wave) similarity solutions and $N$-wave solutions. In terms of Burgers' equation, our small-time asymptotic analysis of the singularity propagation for piecewise-continuous initial conditions illustrates the types of generic behaviours that arise for inner regions when diffusion dominates advection. More generally, this work is a step towards understanding complex-plane behaviour of solutions of nonlinear partial differential equations with non-analytic initial conditions.

nlin.SI