71 citations · 138 across the 9 of their papers we have counts for
3 papers · 2 filters
On the existence of solutions to the operator Riccati equation and the tanΘtheorem
Vadim Kostrykin, Konstantin A. Makarov, Alexander K. Motovilov
Let A and C be self-adjoint operators such that the spectrum of A lies in a gap of the spectrum of C and let d>0 be the distance between the spectra of A and C. We prove that under…
Existence and uniqueness of solutions to the operator Riccati equation. A geometric approach
Vadim Kostrykin, Konstantin A. Makarov, Alexander K. Motovilov
We introduce a new concept of unbounded solutions to the operator Riccati equation and give a complete description of its solutions associated…
On a Subspace Perturbation Problem
Vadim Kostrykin, Konstantin A. Makarov, Alexander K. Motovilov
We discuss the problem of perturbation of spectral subspaces for linear self-adjoint operators on a separable Hilbert space. Let and be bounded self-adjoint operators. Assu…