Well-posedness of the two-dimensional nonlinear Schrödinger equation with concentrated nonlinearity

We consider a two-dimensional nonlinear Schrödinger equation with concentrated nonlinearity. In both the focusing and defocusing case we prove local well-posedness, i.e., existence and uniqueness of the solution for short times, as well as energy and mass conservation. In addition, we prove that this implies global existence in the defocusing case, irrespective of the power of the nonlinearity, while in the focusing case blowing-up solutions may arise.     

Pfaffian solution for coupled discrete nonlinear Schrödinger equation

The Pfaffian solution for the coupled discrete nonlinear Schrödinger equation is studied by using the direct method of soliton theory. The bilinear form of the equation contains a new Pfaffian identity. The Pfaffian representation of Toeplitz determinant is also derived.     

Explicit breather solution of the nonlinear Schrödinger equation

Theoretical and Mathematical Physics - We present a one-line closed-form expression for the three-parameter breather of the nonlinear Schrödinger equation. This provides an analytic proof of...     

Attractors for discrete nonlinear Schrödinger equation with delay

In this paper,we first prove the existence of the global attractor Aν ∈ C（[-ν,0],2）（ν 0） for a weak damping discrete nonlinear Schrdinger equation with delay.Then we consider an upper semi-continuity of Aν as ν → 0＋.     

Positive solutions of a Schrödinger equation with critical nonlinearity

We study the nonlinear Schröodinger equation with critical exponent 2^*= 2 N/( N-2), N 4, where a 0, has a potential well. Using variational methods we establish existence and multiplicity of positive solutions which localize near the potential well for small and large.     

Infinitely many solutions for a nonlinear Schrödinger equation with general nonlinearity

We prove the existence of infinitely many solutions for

$$\begin{aligned} - \Delta u + V(x) u = f(u) \quad \text { in } \mathbb {R}^N, \quad u \in H^1(\mathbb {R}^N), \end{aligned}$$

where V(x) satisfies \(\lim _{|x| \rightarrow \infty } V(x) = V_\infty >0\) and some conditions. We require conditions on f(u) only around 0 and at \(\infty \).

     

The nonlinear Schrödinger equation with a potential

We consider the cubic nonlinear Schrödinger equation with a potential in one space dimension. Under the assumptions that the potential is generic, sufficiently localized, with no bound states, we obtain the long-time asymptotic behavior of small solutions. In particular, we prove that, as time goes to infinity, solutions exhibit nonlinear phase corrections that depend on the scattering matrix associated to the potential. The proof of our result is based on the use of the distorted Fourier transform – the so-called Weyl–Kodaira–Titchmarsh theory – a precise understanding of the “nonlinear spectral measure” associated to the equation, and nonlinear stationary phase arguments and multilinear estimates in this distorted setting.     

Generation mechanism of rogue waves for the discrete nonlinear Schrödinger equation

In this paper, we analyze the generation mechanism of rogue waves for the discrete nonlinear Schrödinger (DNLS) equation from the viewpoint of structural discontinuities. First of all, we derive the analytical breather solutions of the DNLS equation on a new nonvanishing background through the Darboux transformation (DT). Via the explicit expressions of group and phase velocities, we give the parameter conditions for existence of the velocity jumps, which are consistent with the derivation of rogue waves via the generalized DT. Furthermore, to verify such statement, we apply the Taylor expansion to the breather solutions and find that the first-order rogue wave can be obtained at the velocity-jumping point. Our analysis can help to enrich the understanding on the rogue waves for the discrete nonlinear systems.     

On a complex fundamental solution of the Schrödinger equation

A second-order Schrödinger differential operator of parabolic type is considered, for which an explicit form of a fundamental solution is derived. Such operators arise in many problems of physics, and the fundamental solution plays the role of the Feynman propagation function.     

Autoresonance excitation of a soliton of the nonlinear Schrödinger equation

The action of an external parametric perturbation with slowly changing frequency on a soliton of the nonlinear Schrödinger equation is studied. Equations for the time evolution of the parameters of the perturbed soliton are derived. Conditions for the soliton phase locking are found, which relate the rate of change of the perturbation frequency, its amplitude, the wave number, and the phase to the initial data of the soliton. The cases when the initial amplitude of the soliton is small and when the amplitude of the soliton is of the order of unity are considered.     

On a nonlinear Schrödinger equation with a localizing effect

We consider the nonlinear Schrödinger equation associated to a singular potential of the form $a{|u|}^{?(1?m)}u+bu$, for some $m\in (0,1)$, on a possible unbounded domain. We use some suitable energy methods to prove that if $\mathrm{Re}(a)+\mathrm{Im}(a)>0$ and if the initial and right hand side data have compact support then any possible solution must also have a compact support for any $t>0$. This property contrasts with the behavior of solutions associated to regular potentials $(m?1)$. Related results are proved also for the associated stationary problem and for self-similar solution on the whole space and potential $a{|u|}^{?(1?m)}u$. The existence of solutions is obtained by some compactness methods under additional conditions. To cite this article: P. Bégout, J.I. Díaz, C. R. Acad. Sci. Paris, Ser. I 342 (2006).     

Modulation of localized solutions for the Schrödinger equation with logarithm nonlinearity

We investigate the presence of localized analytical solutions of the Schrödinger equation with logarithm nonlinearity. After including inhomogeneities in the linear and nonlinear coefficients, we use similarity transformation to convert the nonautonomous nonlinear equation into an autonomous one, which we solve analytically. In particular, we study stability of the analytical solutions numerically.     

Standing wave solutions for discrete nonlinear Schr?dinger equations with unbounded potentials and saturable nonlinearity

We prove existence and multiplicity results for nontrivial standing waves in discrete nonlinear Schr?dinger equations with unbounded potentials and saturable nonlinearities. Our approach is based on the critical point theory for smooth functionals. Bibliography: 25 titles.     

Integration of a defocusing nonlinear Schrödinger equation with additional terms

Theoretical and Mathematical Physics - The inverse spectral problem method is used to integrate the nonlinear Schrödinger equation with some additional terms in the class of infinite-gap...     

Standing waves to discrete vector nonlinear Schrödinger equation

The purpose of this paper is to study a class of periodic discrete vector nonlinear Schrödinger equation. By using the critical point theory for strongly indefinite problems developed by Ding (Interdisciplinary Mathematical Sciences, World Scientific, Hackensack, NJ, 2007), we prove the existence of non-trivial standing waves for the vector equation with periodic or asymptotically periodic nonlinearities.     

On the existence of dark solitons of the defocusing cubic nonlinear Schrödinger equation with periodic inhomogeneous nonlinearity

We provide a simple proof of the existence of dark solitons of the defocusing cubic nonlinear Schrödinger equation with periodic inhomogeneous nonlinearity. Moreover, our proof allows for a broader class of inhomogeneities and gives some new properties of the solutions. We also apply our approach to the defocusing cubic–quintic nonlinear Schrödinger equation with a periodic potential.     

Asymptotic behavior of solutions of defocusing integrable discrete nonlinear Schrödinger equation

We report our recent result about the long-time asymptotics for the defocusing integrable discrete nonlinear Schr?dinger equation of Ablowitz- Ladik. The leading term is a sum of two terms that oscillate with decay of order t^-1/2     

Chaotic motions for a perturbed nonlinear Schrödinger equation with the power-law nonlinearity in a nano optical fiber

Perturbed nonlinear Schrödinger (NLS) equation with the power-law nonlinearity in a nano optical fiber is studied with the help of its equivalent two-dimensional planar dynamic system and Hamiltonian. Via the bifurcation theory and qualitative theory, equilibrium points for the two-dimensional planar dynamic system are obtained. With the external perturbation taken into consideration, chaotic motions for the perturbed NLS equation with the power-law nonlinearity are derived based on the equilibrium points.