Nearly invariant subspaces for shift semigroups  

作　　者：Yuxia Liang Jonathan R.Partington 

机构地区：[1]School of Mathematical Sciences,Tianjin Normal University,Tianjin 300387,China [2]School of Mathematics,University of Leeds,Leeds LS 29JT,UK

出　　处：《Science China Mathematics》2022年第9期1895-1908,共14页中国科学：数学（英文版）

基　　金：supported by National Natural Science Foundation of China(Grant No.11701422)。

摘　　要：Let{T(t)}_(t≥0) be a C_(0)-semigroupon an infinite-dimensional separable Hilbert space;a suitable definition of near{T(t)^(*)}_(t≥0) invariance of a subspace is presented in this paper.A series of prototypical examples for minimal nearly{S(t)^(*)}_(t≥0) invariant subspaces for the shift semigroup{S(t)}_(t≥0) on L^(2)(0,∞)are demonstrated,which have close links with near T_(θ)^(*)invariance on Hardy spaces of the unit disk for an inner functionθ.Especially,the corresponding subspaces on Hardy spaces of the right half-plane and the unit disk are related to model spaces.This work further includes a discussion on the structure of the closure of certain subspaces related to model spaces in Hardy spaces.

关 键 词：nearly invariant subspace C_(0)-semigroup shift semigroup model space 

分 类 号：O152[理学—数学]