arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2408.00567math.PR
收藏

非厄米随机带矩阵的异常值与有界秩扰动

Outliers and bounded rank perturbation for non-Hermitian random band matrices

Massachusetts Institute of Technology(麻省理工学院)

Yi Han

AI总结:

本研究针对含独立元素的非厄米方形随机带矩阵,证明其有限秩扰动下的谱异常值性质,推广了相关结果并推导收敛速率,还分析了多椭圆随机矩阵乘积的有限秩变形特性。

摘要:

在本研究中,我们考虑一般非厄米方形随机矩阵$X$,其包含一大类具有独立元素的随机带矩阵。尽管这类非均匀模型的极限密度存在性在很大程度上尚不明确,但我们证明当$X$被有限秩确定性矩阵扰动时,谱异常值可在非常一般的条件下确定。更确切地说,当满足$\boldsymbol{\text{E}[X]=0}$、$\boldsymbol{\text{E}[XX^*]=\text{E}[X^*X]=\boldsymbol{1}}$且$\boldsymbol{\text{E}[X^2]=\rho\boldsymbol{1}}$,以及$X$的稀疏性和元素矩满足温和条件时,$X$的所有特征值大概率被限制在参数为$\rho$的椭圆律支撑集的邻域内。此外,有限秩扰动性质成立:当$X$被另一个具有有界秩的确定性矩阵$C_N$扰动时,该扰动会诱导出异常特征值,其极限仅取决于$C_N$的异常特征值和$\rho$。这将Tao关于独立同分布(i.i.d.)随机矩阵的结果,以及O'rourke和Renfrew关于椭圆矩阵的结果,推广到了一类高度稀疏且非均匀的随机矩阵,包括所有正则图上度至少为$(\text{log } N)^3$的高斯带矩阵。我们还推导了定量收敛速率。此外,我们考虑了至少两个独立椭圆随机矩阵乘积的一类有限秩变形,并证明其表现与乘积独立同分布矩阵一致。

英文摘要:

In this work we consider general non-Hermitian square random matrices $X$ that include a wide class of random band matrices with independent entries. Whereas the existence of limiting density is largely unknown for these inhomogeneous models, we show that spectral outliers can be determined under very general conditions when perturbed by a finite rank deterministic matrix. More precisely, we show that whenever $\mathbb{E}[X]=0,\mathbb{E}[XX^*]=\mathbb{E}[X^*X]=\mathbf{1}$ and $\mathbb{E}[X^2]=ρ\mathbf{1}$, and under mild conditions on sparsity and entry moments of $X$, then with high possibility all eigenvalues of $X$ are confined in a neighborhood of the support of the elliptic law with parameter $ρ$. Also, a finite rank perturbation property holds: when $X$ is perturbed by another deterministic matrix $C_N$ with bounded rank, then the perturbation induces outlying eigenvalues whose limit depends only on outlying eigenvalues of $C_N$ and $ρ$. This extends the result of Tao on i.i.d. random matrices and O'rourke and Renfrew on elliptic matrices to a family of highly sparse and inhomogeneous random matrices, including all Gaussian band matrices on regular graphs with degree at least $(\log N)^3$. A quantitative convergence rate is also derived. We also consider a class of finite rank deformations of products of at least two independent elliptic random matrices, and show it behaves just as product i.i.d. matrices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑