发表机构
School of Mathematical Sciences, Fudan University; School of Mathematics, Physics and Statistics, Shanghai Polytechnic University(复旦大学数学科学学院; 上海理工大学数学与统计学院)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
针对带空间白噪声势的三次NLS方程,证明在单个概率为一的事件上,对每个有限切向集合存在线性稳定、实解析的小振幅不变KAM环面族,其参数集相对测度趋于1。
AI 中文摘要
设 \\[ A_\omega=-\partial_x^2+\rho\dot B_x(\omega), \qquad \rho\ne0, \\] 为 $(0,\pi)$ 上带有空间高斯白噪声势的 Dirichlet Schrödinger 算子,通过拟导数逐路径实现。这里 $\dot B_x$ 表示 Brown 运动关于空间变量 $x$ 的分布导数。对于 $\kappa\ne0$,我们考虑三次非线性 Schrödinger 方程 \\[ i u_t=A_\omega u+\kappa |u|^2u. \\] 我们首先证明经典 Wiener 空间上局部实解析函数的零点集定理。作为推论,在单个概率为 1 的事件上,随机特征值的任何非平凡有限支撑整数组合都不为零,并且对于每个有限切向集合,四次扭转矩阵是非奇异的。在固定该事件中的一条路径后,我们将这些定性非退化性质与适用于 KAM 方案的偏四次 Birkhoff 正规形相结合。对于每个有限非空切向集合 $J$(基数为 $b$),我们获得一族线性稳定、实解析、小振幅不变 $b$-环面。该族由 $[\nu,2\nu]^b$ 的 Cantor 子集参数化,其相对测度在 $\nu\to0$ 时趋于 1。
英文摘要
Let \[ A_ω=-\partial_x^2+ρ\dot B_x(ω), \qquad ρ\ne0, \] be the Dirichlet Schrödinger operator on $(0,π)$ with a spatial Gaussian white-noise potential, realized pathwise via quasi-derivatives. Here $\dot B_x$ denotes the distributional derivative of Brownian motion with respect to the spatial variable $x$. For $κ\ne0$, we consider the cubic nonlinear Schrödinger equation \[ i u_t=A_ωu+κ|u|^2u. \] We first prove a zero-set theorem for locally real-analytic functions on classical Wiener space. As a consequence, on a single event of probability one, no nontrivial finitely supported integer combination of the random eigenvalues vanishes, and the quartic twist matrix is nonsingular for every finite tangential set. After fixing a path in this event, we combine these qualitative nondegeneracy properties with a partial quartic Birkhoff normal form adapted to the KAM scheme. For every finite nonempty tangential set \(J\) of cardinality \(b\), we obtain a Cantor family of linearly stable, real-analytic, small-amplitude invariant \(b\)-tori. The family is parametrized by a Cantor subset of \([ν,2ν]^b\) whose relative measure tends to one as \(ν\to0\).