%0 Journal Article
%A Afshin, H.R.
%A Ranjbar, M.A.
%T On the Decomposition of Hilbert Spaces
%J Iranian Journal of Mathematical Sciences and Informatics
%V 6
%N 2
%U http://ijmsi.ir/article-1-232-en.html
%R 10.7508/ijmsi.2011.02.001
%D 2011
%K Numerical range, Davis-Wielandt shell, Spectra, Conjugate of an operator.,
%X 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.
%> http://ijmsi.ir/article-1-232-en.pdf
%P 1-7
%& 1
%!
%9 Research paper
%L A-10-1-94
%+
%G eng
%@ 1735-4463
%[ 2011