数学物理学报 ›› 2025, Vol. 45 ›› Issue (5): 1392-1404.

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一类算子束拟谱的精细刻画与最小拟谱

薛瑞瑶(),侯国林*()   

  1. 内蒙古大学数学科学学院 呼和浩特 010021
  • 收稿日期:2024-11-28 修回日期:2025-01-09 出版日期:2025-10-26 发布日期:2025-10-14
  • 通讯作者: * 侯国林,E-mail:smshgl@imu.edu.cn
  • 作者简介:薛瑞瑶,E-mail:ruiyaoxue@mail.imu.edu.cn
  • 基金资助:
    国家自然科学基金(12261064);国家自然科学基金(11861048);内蒙古自然科学基金(2025MS01026)

The Fine Pseudo-Spectra of a Class of Operator Pencils with Minimal Pseudo-Spectra

Ruiyao Xue(),Guolin Hou*()   

  1. School of Mathematical Science, Inner Mongolia University, Huhhot 010021
  • Received:2024-11-28 Revised:2025-01-09 Online:2025-10-26 Published:2025-10-14
  • Supported by:
    NSFC(12261064);NSFC(11861048);Natural Science Foundation of Inner Mongolia(2025MS01026)

摘要:

$T, S$ 分别是 Hilbert 空间 $\mathcal{X}$ 中的稠定闭线性算子和有界线性算子, $\lambda S-T$ 表示一次算子束. 该文刻画了算子束的拟谱、拟点谱、拟连续谱和拟剩余谱的结构, 并得出算子束的广义拟谱等于其最小拟谱的充要条件. 设 $H$ 是 Hamilton 算子, $J$ 是辛单位算子, 之后得到了算子束 $\lambda J-H$ 的拟谱及其细分的对称性, 并论证了拟谱与其广义拟谱相等, 且等于其最小拟谱. 最后用例子进行了辅证.

关键词: 算子束, 拟谱, 分块算子矩阵, Hamilton 算子

Abstract:

Let $T$ and $S$ be densely defined closed linear operators and bounded linear operators in the Hilbert space $\mathcal{X}$, respectively. Denote by $\lambda S - T$ the operator pencils. This paper investigates the structure of the fine pseudo-spectra of $\lambda S - T$, including pseudo-point spectra, pseudo-continuous spectra, and pseudo-residual spectra. Furthermore, a necessary and sufficient condition is derived for the equality of the generalized pseudo-spectra of operator pencils to the minimal pseudo-spectra. Let $H$ denote Hamiltonian operators and $J$ denote symplectic identity operators; the symmetries of the pseudo-spectra and their subdivisions for the operator pencils $\lambda J - H$ are obtained. Additionally, it is proven that the pseudo-spectra of $\lambda J - H$ coincide with both the generalized pseudo-spectra and the minimal pseudo-spectra. Finally, an illustrative example is provided to substantiate the theoretical conclusions.

Key words: operator pencils, pseudo-spectra, operator matrices, Hamiltonian operators

中图分类号: 

  • O175.3