Local behavior of solutions of the stationary Schr\" odinger equation with singular potentials and bounds on the density of states of Schrödinger operators
In this paper, we consider the large time asymptotic behavior of solutions to systems of two cubic nonlinear Schr"odinger equations in one space dimension. It turns out that for a system there exists a small solution of which asymptotic profile is a sum of two parts oscillating in a different way. This kind of behavior seems new. Further, several examples of systems which admit solution with several types of behavior such as modified scattering, nonlinear amplification, and nonlinear dissipation, are given. We also extend our previous classification result of nonlinear cubic systems.
We consider a derivative nonlinear Schr{ö}dinger equation with general nonlinearlity: i$\partial$tu + $\partial$ 2 x u + i|u| 2$σ$ $\partial$xu = 0, In [12], the authors prove the stability of two solitary waves in energy space for $σ$ $\in$ (1, 2). As a consequence, there exists a two-soliton trains in energy space for $σ$ $\in$ (1, 2). Our goal in this paper is proving the existence of multi-soliton trains in energy space for $σ$ 5 2. Our proofs proceed by xed point arguments around the desired prole, using Strichartz estimates.
We consider the following triple power nonlinear Schr{ö}dinger equation: iut + $Δ$u + a 1 |u|u + a 2 |u| 2 u + a 3 |u| 3 u = 0. We are interested in algebraic standing waves i.e standing waves with algebraic decay above equation in dimensions n (n = 1, 2, 3). We prove the instability of these solutions in the cases DDF (we use abbreviation D: defocusing (ai < 0), F:focusing (ai > 0)) and DFF when n = 2, 3 and in the case DFF with a1 = --1, a3 = 1 and a2 < 32/15$\sqrt$6 when n = 1. Under these assumptions, the standing waves are orbitally unstable in the case of small positive frequency. When t…
Long Range Scattering for the Modified Schr"odinger Map in two space dimensions
本文研究了二维空间中修正Schr“odinger映射解的时间渐近性态和散射理论。我们解决了柯西问题与大有限的初始时间,直到无穷大的时间,我们确定的渐近行为,从而获得的解决方案的时间。作为一个副产品,我们获得了H^k inter FH^k中小数据的全局存在性,其中k > 1。我们还解决了柯西问题的无限初始时间,即我们构造的解决方案定义在一个邻域的无穷大的时间,规定的渐近行为的前一种类型。
In this paper, we study the existence of traveling waves for a fourth order Schr\" odinger equations with mixed dispersion, that is, solutions to $$Δ^2 u +βΔu +i V \nabla u +αu =|u|^{p-2} u,\ in\ \R^N ,\ N\geq 2.$$ We consider this equation in the Helmholtz regime, when the Fourier symbol $P$ of our operator is strictly negative at some point. Under suitable assumptions, we prove the existence of solution using the dual method of Evequoz and Weth provided that $p\in (p_1 , 2N/(N-4)_+)$. The real number $p_1$ depends on the number of principal curvature of $M$ staying bounded away from $0$, whe…
Positive Least Energy Solutions and Phase Separation for Coupled Schrodinger Equations with Critical Exponent: Higher Dimensional Case
We study the following nonlinear Schrödinger system which is related to Bose-Einstein condensate: {displaymath} {cases}-Δu + \la_1 u = μ_1 u^{2^ \ast -1}+βu^{ \frac{2^\ast}{2} -1}v^{ \frac{2^\ast}{2} }, \quad x \in Ω, -Δv + \la_2 v =μ_2 v^{2^ \ast -1}+βv^{ \frac{2^\ast}{2} -1} u^{ \frac{2^\ast}{2} }, \quad x \in \om , u \ge 0, v \ge 0 \,\, \hbox{in $\om$} , \quad u=v=0 \,\, \hbox{on $\partial\om$} .{cases}{displaymath} Here $\om\subset \R^N$ is a smooth bounded domain, $2^\ast:=\frac{2N}{N-2}$ is the Sobolev critical exponent, $-\la_1(\om)<\la_1,\la_2<0$ , $μ_1,μ_2>0$ and $β\neq 0$ , where $λ_…
We give necessary and sufficient conditions for the controllability of a Schr\''odinger equation involving the sub-Laplacian of a nilmanifold obtained by taking the quotient of a group of Heisenberg type by one of its discrete sub-groups.This class of nilpotent Lie groups is a major example of stratified Lie groups of step 2. The sub-Laplacian involved in these Schr\''odinger equations is subelliptic, and, contrarily to what happens for the usual elliptic Schr\''odinger equation for example on flat tori or on negatively curved manifolds, there exists a minimal time of controllability. The main…
This paper concerns inverse problems for strongly coupled Schrödinger equations. The purpose of this inverse problem is to retrieve a stationary potential in the strongly coupled Schrödinger equations from either boundary or internal measurements. Two stability results are derived from a new Carleman estimate for the strongly coupled Schrödinger equations.
Let $H:=-Δ+V$ be a nonnegative Schrödinger operator on $L^2({\bf R}^N)$, where $N\ge 2$ and $V$ is an inverse square potential. In this paper we obtain sharp decay estimates of the operator norms of $e^{-tH}$ and $\nabla e^{-tH}$ in Lorentz spaces.
In this paper, we consider the energy critical nonlinear Schrödinger equation with a repulsive inverse square potential. In particular, we deal with radial initial data, whose energy is equal to the energy of static solution to the corresponding nonlinear Schrödinger equation without a potential. We investigate time behavior of the radial solutions with such initial data.
We study an inverse source scattering problem for the Schrödinger equation with a quadratic nonlinearity. In general, uniqueness of inverse source problems can not be guaranteed at a fixed energy. Therefore, additional information is required for the source in order to obtain a unique solution. By adding reference point sources, we show that a general source function could be uniquely determined from boundary measurements at a fixed wavenumber. This method does not apply to inverse source problems of linear equations since it uses the nonlinearity as a tool. The proof utilizes the method of li…