@ARTICLE{Afshin,
author = {Afshin, H.R. and Ranjbar, M.A. and },
title = {On the Decomposition of Hilbert Spaces},
volume = {6},
number = {2},
abstract ={Basic relation between numerical range and Davis-Wielandt shell of an operator $A$ acting on a Hilbert space with orthonormal basis $xi={e_{i}|i in I}$ and its conjugate $bar{A}$ which is introduced in this paper are obtained. The results are used to study the relation between point spectrum, approximate spectrum and residual spectrum of $A$ and $bar{A}$. A necessary and sufficient condition for $A$ to be self-conjugate ($A=bar{A}$) is given using a subgroup of H. },
URL = {http://ijmsi.ir/article-1-232-en.html},
eprint = {http://ijmsi.ir/article-1-232-en.pdf},
journal = {Iranian Journal of Mathematical Sciences and Informatics},
doi = {10.7508/ijmsi.2011.02.001},
year = {2011}
}