Low-regularity Schrödinger maps

Schrödinger映射到二维Kähler流形

Schr{ö}dinger maps to a K{ä}hler manifold in two dimensions

本文研究了Schrödinger映射到二维Kähler流形的全局存在性和散射性质，采用小初始数据和Besov空间方法进行证明。

某些度量图上超临界非线性Schr{ö}dinger方程驻波解的存在性

Existence of stationary solutions of supercritical nonlinear Schr{ö}dinger equations on some metric graphs

本文研究了非紧连通度量图上的超临界非线性Schr{ö}dinger方程，在无小质量假设下证明了具预定质量的驻波解的存在性。

A Liouville theorem for the Chern--Simons--Schr{ö}dinger equation

In this paper we prove a Liouville theorem for the Chern--Simons--Schr{ö}dinger equation. This result is consistent with the soliton resolution conjecture for initial data that does not lie in a weighted space. See [KKO22] for the soliton resolution result in a weighted space.

Scattering for the defocusing, cubic nonlinear Schr{ö}dinger equation with initial data in a critical space

In this note we prove scattering for a defocusing nonlinear Schr{ö}dinger equation with initial data lying in a critical Besov space. In addition, we obtain polynomial bounds on the scattering size as a function of the critical Besov norm.

双幂次薛定谔方程的质量-能量散射准则

Mass-energy Scattering Criterion For Double Power Schr{ö}dinger Equations

本文研究双幂次薛定谔方程，将散射结果推广至所有L2超临界幂次，并适用于能量超临界非线性情形。

非自对偶 Chern–Simons–Schrödinger 方程在孤子层面的刚性

Rigidity for the non self-dual Chern--Simons--Schr{ö}dinger equation at the level of the soliton

本文在孤子层面为非自对偶 Chern–Simons–Schrödinger 方程的解建立了刚性结论。

On a stationary Schr{ö}dinger equation with periodic magnetic potential

We prove existence results for a stationary Schr{ö}dinger equation with periodic magnetic potential satisfying a local integrability condition on the whole space using a critical value function.

Around plane waves solutions of the Schr{ö}dinger-Langevin equation

We consider the logarithmic Schr{ö}dinger equations with damping, also called Schr{ö}dinger-Langevin equation. On a periodic domain, this equation possesses plane wave solutions that are explicit. We prove that these solutions are asymptotically stable in Sobolev regularity. In the case without damping, we prove that for almost all value of the nonlinear parameter, these solutions are stable in high Sobolev regularity for arbitrary long times when the solution is close to a plane wave. We also show and discuss numerical experiments illustrating our results.

Global well-posedness and scattering for the defocusing, energy -critical, nonlinear Schr{ö}dinger equation in the exterior of a convex obstacle when $d = 4$

In this paper we prove that the energy - critical nonlinear Schr{ö}dinger equation in the domain exterior to a convex obstacle is globally well - posed and scattering for initial data having finite energy. To prove this we utilize frequency localized Morawetz estimates adapted to an exterior domain.

Dynamics of the Schr{ö}dinger-Langevin Equation

We consider the nonlinear Schr{ö}dinger-Langevin equation for both signs of the logarithmic nonlinearity. We explicitly compute the dynamics of Gaussian solutions for large times, which is obtained through the study of a particular nonlinear differential equation of order 2. We then give the asymptotic behavior of general energy weak solutions under some regularity assumptions. Some numerical simulations are performed in order to corroborate the theoretical results.

The cubic Schr{ö}dinger regime of the Landau-Lifshitz equation with a strong easy-axis anisotropy

We pursue our work on the asymptotic regimes of the Landau-Lifshitz equation for bi-axial ferromagnets. We put the focus on the cubic Schr{ö}dinger equation, which is known to describe the dynamics in a regime of strong easy-axis anisotropy. In any dimension, we rigorously prove this claim for solutions with sufficient regularity. In this regime, we additionally classify the one-dimensional solitons of the Landau-Lifshitz equation and quantify their convergence towards the solitons of the one-dimensional cubic Schr{ö}dinger equation.

Some remarks on Schr{ö}dinger operators

The problem we consider is given a mixed model $F(γ) \rightarrow γ\rightarrow \tildeγ$ and a potential $\widehat{V}$ such that $\log \widehat{V} \in L^{1}$, to determine a movement $U$ such that $F(U γ)=F(γ) + \widehat{V}$.

一类拟线性薛定谔方程的数学研究

A quasi-linear Schr{ö}dinger equation for nucleons : existence, uniqueness and asymptotic behavior

本文研究原子核粒子动力学中的拟线性薛定谔方程，在参数假设下证明正径向解的存在性、唯一性与非退化性，并分析解对参数的依赖。

Stability of multi-solitons for the derivative nonlinear Schr{ö}dinger equation

The nonlinear Schr{ö}dinger equation with derivative cubic nonlinearity admits a family of solitons, which are orbitally stable in the energy space. In this work, we prove the orbital stability of multi-solitons configurations in the energy space, under suitable assumptions on the speeds and frequencies of the composing solitons. The main ingredients of the proof are modulation theory, energy coercivity and monotonicity properties.

高斯测度的演化及其在一维非线性 Schrödinger 方程中的应用

Evolution of Gaussian measures and application to the one dimensional nonlinear Schr{ö}dinger equation

本文概述文献[3]关于随机初值下一维非线性 Schrödinger 方程的研究，通过刻画高斯测度的非线性演化，得到方程的整体适定性与散射结论。

Littlewood-Paley-Stein functions for Hodge-de Rham and Schr{ö}dinger operators

We study the Littlewood-Paley-Stein functions associated with Hodge-de Rham and Schr{ö}dinger operators on Riemannian manifolds. Under conditions on the Ricci curvature we prove their boundedness on L p for p in some interval (p 1 , 2] and make a link to the Riesz Transform. An important fact is that we do not make assumptions of doubling measure or estimates on the heat kernel in this case. For p > 2 we give a criterion to obtain the boundedness of the vertical Littlewood-Paley-Stein function associated with Schr{ö}dinger operators on L p .

On the derivative nonlinear Schr{ö}dinger equation on the half line with Robin boundary condition

We consider the Schrödinger equation with nonlinear derivative term on $[0,+\infty)$ under Robin boundary condition at $0$. Using a virial argument, we obtain the existence of blowing up solutions and using variational techniques, we obtain stability and instability by blow up results for standing waves.

Higher Dimensional Vortex Standing Waves for Nonlinear Schr{ö}dinger Equations

We study standing wave solutions to nonlinear Schr{ö}dinger equations, on a manifold with a rotational symmetry, which transform in a natural fashion under the group of rotations. We call these vortex solutions. They are higher dimensional versions of vortex standing waves that have been studied on the Euclidean plane. We focus on two types of vortex solutions, which we call spherical vortices and axial vortices.

Blow up of the solutions to a linear elliptic system involving Schr{ö}dinger operators

We show how the solutions to a $2\times2$ linear system involving Schr{ö}dinger operators blow up as the parameter $μ$ tends to some critical value which is the principal eigenvalue of the system; here the potential is continuous positive with superquadratic growth and the square matrix of the system is with constant coefficients and may have a double eigenvalue.

Uniformly accurate time-splitting methods for the semiclassical linear Schr{ö}dinger equation

This article is devoted to the construction of numerical methods which remain insensitive to the smallness of the semiclassical parameter for the linear Schr{ö}dinger equation in the semiclassical limit. We specifically analyse the convergence behavior of the first-order splitting. Our main result is a proof of uniform accuracy. We illustrate the properties of our methods with simulations.

The perturbational stability of the Schr$\ddot{o}$dinger equation

By using the Wigner transform, it is shown that the nonlinear Schr$\ddot{\textmd{o}}$dinger equation can be described, in phase space, by a kinetic theory similar to the Vlasov equation which is used for describing a classical collisionless plasma. In this paper we mainly show Landau damping in the quantum sense, namely,quantum Landau damping exists for the Wigner-Poisson system. At the same time, we also prove the existence and the stability of the nonlinear Schr$\ddot{\textmd{o}}$dinger equation under the quantum stability assumption.

On The Cauchy Problem For A Derivative Nonlinear Schr{ö}Dinger Equation With Nonvanishing Boundary Conditions

In this paper we consider the Schr{ö}dinger equation with nonlinear derivative term. Our goal is to initiate the study of this equation with non vanishing boundary conditions. We obtain the local well posedness for the Cauchy problem on Zhidkov spaces X k (R) and in $ϕ$ + H k (R). Moreover, we prove the existence of conservation laws by using localizing functions. Finally, we give explicit formulas for stationary solutions on Zhidkov spaces.

Modified scattering for the cubic Schr{ö}dinger equation on product spaces: the nonresonant case

We consider the cubic nonlinear Schr{ö}dinger equation on the spatial domain $\mathbb{R}\times \mathbb{T}^d$, and we perturb it with a convolution potential. Using recent techniques of Hani-Pausader-Tzvetkov-Visciglia, we prove a modified scattering result and construct modified wave operators, under generic assumptions on the potential. In particular, this enables us to prove that the Sobolev norms of small solutions of this nonresonant cubic NLS are asymptotically constant.

Multi-speed solitary waves of nonlinear Schr{ö}dinger systems: theoretical and numerical analysis

We consider a system of coupled nonlinear Schr{ö}dinger equations in one space dimension. First, we prove the existence of multi-speed solitary waves, i.e solutions to the system with each component behaving at large times as a solitary wave. Then, we investigate numerically the interaction of two solitary waves supported each on one component. Among the possible outcomes, we find elastic and inelastic interactions, collision with mass extraction and reflexion.

一般非线性 Schrödinger 方程的轮廓分解与散射

Profile decomposition and scattering for general nonlinear Schr{ö}dinger equations

本文研究一般扰动非线性的 Schrödinger 方程，构建了相应的轮廓分解，并在能量超临界且临界 Sobolev 范数有界的假设下证明了全局存在性与散射，推广了双幂非线性的已有成果。

具有奇异非线性项的某些稳态 Schrödinger 方程解支集局部化的一种更敏锐的能量方法

A sharper energy method for the localization of the support to some stationary Schr{ö}dinger equations with a singular nonlinearity

本文针对具有奇异非线性项的稳态 Schrödinger 方程，提出了一种更敏锐的能量方法，并据此证明了解的支集紧致性。

Global well-posedness for the cubic nonlinear Schr{ö}dinger equation with initial lying in $L^{p}$-based Sobolev spaces

In this paper we continue our study [DSS20] of the nonlinear Schrödinger equation (NLS) with bounded initial data which do not vanish at infinity. Local well-posedness on $\mathbb{R}$ was proved for real analytic data. Here we prove global well-posedness for the 1D NLS with initial data lying in $L^{p}$ for any $2 < p < \infty$, provided the initial data is sufficiently smooth. We do not use the complete integrability of the cubic nonlinear Schr{ö}dinger equation.

Global well-posedness and scattering for the defocusing, $L^{2}$-critical, nonlinear Schr{ö}dinger equation when $d \geq 3$

In this paper we prove that the defocusing, $d$-dimensional mass critical nonlinear Schr{ö}dinger initial value problem is globally well-posed and scattering for $u_{0} \in L^{2}(\mathbf{R}^{d})$ and $d \geq 3$. To do this, we will prove a frequency localized interaction Morawetz estimate similar to the estimate made in [10]. Since we are considering an $L^{2}$ - critical initial value problem we will localize to low frequencies.

Stability estimate for an inverse problem for the Schr{ö}dinger equation in a magnetic field with time-dependent coefficient

We study the stability issue in the inverse problem of determining the magnetic field and the time-dependent electric potential appearing in the Schrödinger equation, from boundary observations. We prove in dimension 3 or greater, that the knowledge of the Dicrichlet-to-Neumann map stably determines the magnetic field and the electric potential.

Almost Morawetz estimates and global well-posedness for the defocusing $L^2$-critical nonlinear Schr{ö}dinger equation in higher dimensions

In this paper, we consider the global well-posedness of the defocusing, $L^{2}$ - critical nonlinear Schr{ö}dinger equation in dimensions $n \geq 3$. Using the I-method, we show the problem is globally well-posed in $n = 3$ when $s > {2/5}$, and when $n \geq 4$, for $s > \frac{n - 2}{n}$. We combine energy increments for the I-method, interaction Morawetz estimates, and almost Morawetz estimates to prove the result.

Global well-posedness and scattering for the defocusing, $L^{2}$-critical, nonlinear Schr{ö}dinger equation when $d = 2$

In this paper we prove that the defocusing, cubic nonlinear Schr{ö}dinger initial value problem is globally well-posed and scattering for $u_{0} \in L^{2}(\mathbf{R}^{2})$. To do this, we will prove a frequency localized interaction Morawetz estimate similar to the estimate made in \cite{CKSTT4}. Since we are considering an $L^{2}$ - critical initial value problem we will localize to low frequencies.

具约束势的 Schrödinger 方程的平滑效应与量子-经典对应

Smoothing effect and quantum-classical correspondence for the Schr{ö}dinger equation with confining potential

本文研究具次二次约束势的 Schrödinger 方程，证明其解的局部平滑效应等价于对应经典流的逃逸率估计，并借助 Egorov 定理建立量子-经典对应。

Local dispersive and Strichartz estimates for the Schr{ö}dinger operator on the Heisenberg group

It was proved by H. Bahouri, P. G{é}rard and C.-J. Xu in [9] that the Schr{ö}dinger equation on the Heisenberg group $\mathbb{H}^d$, involving the sublaplacian, is an example of a totally non-dispersive evolution equation: for this reason global dispersive estimates cannot hold. This paper aims at establishing local dispersive estimates on $\mathbb{H}^d$ for the linear Schr{ö}dinger equation, by a refined study of the Schr{ö}dinger kernel $S_t$ on $\mathbb{H}^d$. The sharpness of these estimates is discussed through several examples. Our approach, based on the explicit formula of the heat kern…

薛定谔-泊松方程解的指数稳定性

Exponential stability of solutions to the Schr{ö}dinger-Poisson equation

本研究证明了无外参数圆周上Gevrey类薛定谔-泊松方程小解的指数稳定性，给出了最优时间量级，验证了Bourgain的相关猜想。

Bilinear Strichartz estimates for the Schr{ö}dinger map problem

In this paper we prove bilinear Strichartz estimates for a solution to the Schr{ö}dinger map problem whose size is small in the critical Strichartz space $| |\nabla|^{\frac{d - 2}{2}} ψ_{x} |_{L_{t,x}^{\frac{2(d + 2)}{d}}}$. These estimates will be useful in an upcoming paper in proving a local well - posedness result. Bilinear estimates make use of an argument similar to the argument found in Planchon and Vega (2009). We use the same gauges as in Bejenaru, Ionescu and Kenig (2007), Bejenaru et al. (2011), and Smith.

关于对数Schrödinger方程高正则性的传播

On the propagation of high regularity for the logarithmic Schr{ö}dinger equation

该文研究一维对数Schrödinger方程的高正则性传播，证明一类奇初值下$s>7/2$时$H^s$范数瞬时爆破，特定奇解在Neumann边界下保持$H^3$正则性，且结果获数值模拟验证。

Construction of multi-solitons and multi kink-solitons of derivative nonlinear Schr{ö}dinger equations

We look for solutions to derivative nonlinear Schrodinger equations built upon solitons. We prove the existence of multi-solitons i.e. solutions behaving at large time as the sum of finite solitons. We also show that one can attach a kink at the begin of the sum of solitons i.e multi kink-solitons. Our proofs proceed by fixed point arguments around the desired profile, using Strichartz estimates.

Finite time extinction for a damped nonlinear Schr{ö}dinger equation in the whole space

We consider a nonlinear Schr{ö}dinger equation set in the whole space with a single power of interaction and an external source. We first establish existence and uniqueness of the solutions and then show, in low space dimension, that the solutions vanish at a finite time. Under a smallness hypothesis of the initial data and some suitable additional assumptions on the external source, we also show that we can choose the upper bound on which time the solutions vanish.

On smoothness and uniqueness of multi-solitons of the non-linear Schr{ö}dinger equations

In this paper, we study some properties of multi-solitons for the non-linear Schr{ö}dinger equations in R^d with general non-linearities. Multi-solitons have already been constructed in H^1, successively by Merle, by Martel and Merle, and by C{ô}te, Martel and Merle. We show here that multi-solitons are smooth, depending on the regularity of the non-linearity. We obtain also a result of uniqueness in some class, either when the ground states are all stable, or in the mass-critical case.

Spectral Inequalities for the Schr{ö}dinger operator

In this paper we deal with the so-called "spectral inequalities", which yield a sharp quantification of the unique continuation for the spectral family associated with the Schrödinger operator in $ \mathbb{R}^d$ \begin{equation*} H_{g,V} = Δ_g + V(x), \end{equation*} where $Δ_g$ is the Laplace-Beltrami operator with respect to an analytic metric $g$, which is a perturbation of the Euclidean metric, and $V(x)$ a real valued analytic potential vanishing at infinity.

Analysis of stability and instability for standing waves of the double power one dimensional nonlinear Schr{ö}dinger equation

For the double power one dimensional nonlinear Schr{ö}dinger equation, we establish a complete classification of the stability or instability of standing waves with positive frequencies. In particular, we fill out the gaps left open by previous studies. Stability or instability follows from the analysis of the slope criterion of Grillakis, Shatah and Strauss. The main new ingredients in our approach are a reformulation of the slope and the explicit calculation of the slope value in the zero-frequency case. Our theoretical results are complemented with numerical experiments.

Some nonexistence results for space-time fractional Schr{ö}dinger equations without gauge invariance

In this paper, we consider the Cauchy problem in $\mathbb{R}^N$, $N\geq1$, for semi-linear Schrödinger equations with space-time fractional derivatives. We discuss the nonexistence of global $L^1$ or $L^2$ weak solutions in the subcritical and critical cases under some conditions on the initial data and the nonlinear term. Furthermore, the nonexistence of local $L^1$ or $L^2$ weak solutions in the supercritical case are studied.

具有良好预备随机初始数据的二次非线性薛定谔方程的长时适定性与波湍流极限

Long time well-posedness and wave turbulence limit for a quadratic non-lienar Schr{ö}dinger equation with well prepared random initial data

本文证明二次非线性薛定谔方程在随机初始数据下的长时适定性，并在高维情形推导波动力学方程，方法基于Deng和Hani的思想。

Spatial decay of multi-solitons of the generalized Korteweg-de Vries and nonlinear Schr{ö}dinger equations

We study pointwise spatial decay of multi-solitons of the generalized Korteweg-de Vries equations. We obtain that, uniformly in time, these solutions and their derivatives decay exponentially in space on the left of and in the solitons region, and prove rapid decay on the right of the solitons. We also prove the corresponding result for multi-solitons of the nonlinear Schr{ö}dinger equations, that is, exponential decay in the solitons region and rapid decay outside.

Almost global existence for some nonlinear Schr{ö}dinger equations on $\mathbb{T}^d$ in low regularity

We are interested in the long time behavior of solutions of the nonlinear Schr{ö}dinger equation on the $d$-dimensional torus in low regularity, i.e. for small initial data in the Sobolev space $H^{s_0}(\mathbb T^d)$ with $s_0>d/2$. We prove that, even in this context of low regularity, the $H^s$-norms, $s\geq 0$, remain under control during times, $T_\varepsilon= \exp \big(-\frac{|\log\varepsilon|^2}{4\log|\log\varepsilon|} \big)$, exponential with respect to the initial size of the initial datum in $H^{s_0}$, $\|u(0)\|_{H^{s_0}}=\varepsilon$. For this, we add to the linear part of the equati…

具有光滑 $L^2$-次临界函数非线性扰动的对数 Schrödinger 方程多孤子的存在性

Existence of multi-solitons for logarithmic Schr{ö}dinger equation with a perturbation of a smooth $L^2$-subcritical function nonlinearity

本文针对含聚焦对数项和光滑 $L^2$-次临界函数非线性的 Schrödinger 方程，通过迭代构造与局部能量估计，证明了多孤子解的存在性，其渐近表现为多个不同速度孤子的叠加。

含时薛定谔方程最小二乘形式的低复杂度逼近

Low-complexity approximations with least-squares formulation of the time-dependent Schr{ö}dinger equation

本文提出基于张量和高斯波包线性组合逼近含时薛定{ö}dinger方程解的新方法，将其转化为受限优化问题，分别采用Alternating Least Square算法和贪婪算法求解，并讨论了两者效率。

Dispersive estimates for the Schr{ö}dinger equation in a strictly convex domain and applications

We consider an anisotropic model case for a strictly convex domain of dimension $d\geq 2$ with smoothboundary and we describe dispersion forthe semi-classical Schr{ö}dinger equation with Dirichlet boundary condition. More specifically, we obtain the following fixed time decay rate for the linear semi-classical flow : a loss of $(\frac ht)^{1/4}$ occurs with respect to the boundary less case due to repeated swallowtail type singularities, and is proven optimal. Corresponding Strichartz estimates allow to solve the cubic nonlinear Schödinger equation on such a 3D model convex domain, hence match…

环面 $\mathbb{T}$ 上质量临界非线性薛定谔方程的全局适定性

Global well--posedness for the mass--critical nonlinear Schr{ö}dinger equation on $\mathbb{T}$

本文证明环面上五次非线性薛定谔方程在 $H^s(\mathbb{T})$ ($s>1/3$) 初值下的全局适定性，改进了此前 $s>2/5$ 的最佳结果。

带幂律非线性扰动的对数薛定谔方程的柯西问题

The Cauchy problem for logarithmic Schr{ö}dinger equation with a perturbation of power law nonlinearity

研究带对数与多项式增长非线性项的薛定谔方程柯西问题，在次临界情形构造能量空间解，并讨论临界情形的全局存在条件及更一般的柯西理论。

欧几里得空间中具有次二次约束势的 Schrödinger 方程的能观性

Observability of the Schr{ö}dinger equation with subquadratic confining potential in the Euclidean space

本文研究至多二次增长约束势下 Schrödinger 方程的能观性，利用半经典分析刻画满足正则性的观测开集，并估计最优观测时间。

非线性薛定谔方程中具有正则性损失的病态集合

Pathological set with loss of regularity for nonlinear Schr{ö}dinger equations

本文针对质量超临界散焦非线性薛定谔方程，通过多尺度气泡叠加构造稠密初始数据，并利用可压缩 Euler 方程和重整化调制能量泛函证明任意短时间内的正则性损失。

Symmetry of Positive Solutions for the Fractional Schr$ \ddot{\textrm{o}}$dinger Equations with Choquard-type Nonlinearities

This paper deals with the following fractional Schr$ \ddot{\textrm{o}}$dinger equations with Choquard-type nonlinearities \begin{equation*} \left\{\begin{array}{r@{\ \ }c@{\ \ }ll} (-Δ)^{\fracα{2}}u + u - C_{n,-β} \,(|x|^{β-n}\ast u^{p})\, u^{p-1}& = &0 & \mbox{in}\ \ \mathbb{R}^{n}\,, \\[0.05cm] u & > & 0 & \mbox{on}\ \ \mathbb{R}^{n}, \end{array}\right. \end{equation*} where $ 0< α,β< 2, 1\leq p <\infty \,\,and\,\, n\geq 2. $ First we construct a decay result at infinity and a narrow region principle for related equations. Then we establish the radial symmetry of positive solutions for the a…

Global well-posedness and scattering for nonlinear Schr{ö}dinger equations with algebraic nonlinearity when $d = 2, 3$, $u_{0}$ radial

In this paper we discuss global well - posedness and scattering for some initial value problems that are $L^{2}$ supercritical and $\dot{H}^{1}$ subcritical, with radial data. We prove global well - posedness and scattering for radial data in $H^{s}$, $s > s_{c}$, where the problem is $\dot{H}^{s_{c}}$ - critical. We make use of the long time Strichartz estimates of \cite{D2} to do this.