5 citations · 8 across the 12 of their papers we have counts for
14 papers
When is the sum of closed subspaces of a Hilbert space closed?
Ivan Feshchenko
We provide a sufficient condition for a finite number of closed subspaces of a Hilbert space to be linearly independent and their sum to be closed. Under this condition a formula f…
On the inverse best approximation property of systems of subspaces of a Hilbert space
Ivan Feshchenko
Let be a Hilbert space and be closed subspaces of . Denote by the orthogonal projection onto , . Following Patrick L. Combettes and Nol…
On the optimal error bound for the first step in the method of cyclic alternating projections
Ivan Feshchenko
Let be a Hilbert space and be closed subspaces of . Set and let be the orthogonal projection onto , .…
Realization of the Werner-Holevo and Landau-Streater quantum channels for qutrits on quantum computers
A. I. Pakhomchik, I. Feshchenko, A. Glatz +5
We realize Landau-Streater (LS) and Werner-Holevo (WH) quantum channels for qutrits on the IBM quantum computers. These channels correspond to interaction between the qutrit and it…
When is the sum of complemented subspaces complemented?
Ivan Feshchenko
We provide a sufficient condition for the sum of a finite number of complemented subspaces of a Banach space to be complemented. Under this condition a formula for a projection ont…
On the closedness of the sum of ranges of operators with almost compact products
Ivan S. Feshchenko
Let be complex Hilbert spaces and be a bounded linear operator with the closed range ,…