Normal Projections in Krein Spaces
Normal Projections in Krein Spaces
复制标题
DOI:
10.1007/s00020-013-2063-3
复制
发表时间:
2013-05
影响因子:
0.8
通讯作者:
A. Maestripieri;F. Martínez Pería
中科院分区:
文献类型:
--
作者:
A. Maestripieri;F. Martínez Pería
Given a complex Krein space H with fundamental symmetry J, the aim of this note is to characterize the set of J-normal projections Q={Q∈L(H):Q2=QandQ#Q=QQ#}. The ranges of the projections in QQ are exactly those subspaces of HH which are pseudo-regular. For a fixed pseudo-regular subspace S , there are infinitely many J-normal projections onto it, unless SS is regular. Therefore, most of the material herein is devoted to parametrizing the set of J-normal projections onto a fixed pseudo-regular subspace S.