Title of article :
A characterization of orthogonality preserving operators
Author/Authors :
Ansari-piri ، E. - University of Guilan , Sanati ، R.G. - ACECR(Academic Center of Education and Culture Research), Rasht branch , Kardel ، M. - University of Guilan, University Campus 2
Abstract :
In this paper, we characterize the class of orthogonality preserving operators on an infinite-dimensional Hilbert space H as scalar multiples of unitary operators between H and some closed subspaces of H. We show that any circle (centered at the origin) is the spectrum of an orthogonality preserving operator. Also, we prove that every compact normal operator is a strongly orthogonality preserving operator.
Keywords :
Orthogonality preserving operators , adjoint of operators , isometry , unitary operators
Journal title :
Bulletin of the Iranian Mathematical Society
Journal title :
Bulletin of the Iranian Mathematical Society
