The effect of finite rank perturbations on Jordan chains of linear operators

A general result on the structure and dimension of the root subspaces of a linear operator under finite rank perturbations is proved: The increase of dimension from the kernel of the <i>n</i>-th power to the kernel of the (<i>n</i>+1)-th power of the perturbed operator differ...

Full description

Bibliographic Details
Authors: Behrndt, Jussi, Leben, Leslie, Martínez Pería, Francisco Dardo, Trunk, Carsten
Format: article
Status:Published version
Publication Date:2015
Country:Argentina
Institution:Universidad Nacional de La Plata
Repository:SEDICI (UNLP)
Language:English
OAI Identifier:oai:sedici.unlp.edu.ar:10915/86002
Online Access:http://sedici.unlp.edu.ar/handle/10915/86002
Access Level:Open access
Keyword:Ciencias Exactas
Matemática
Finite rank perturbation
Jordan chain
Root subspace
Description
Summary:A general result on the structure and dimension of the root subspaces of a linear operator under finite rank perturbations is proved: The increase of dimension from the kernel of the <i>n</i>-th power to the kernel of the (<i>n</i>+1)-th power of the perturbed operator differs from the increase of dimension of the kernels of the corresponding powers of the unperturbed operator by at most the rank of the perturbation. This bound is sharp.