3 papers
math.FA2021
Orthogonality in normed spaces
Boris Burshteyn, Alexander Volberg
Motivated by the questions in the theory of Fredholm stability in Banach space and Kato's strictly singular operators we answer several natural questions concerning ``orthogonality…
math.FA2009
Strictly Singular Uniform Adjustment in Banach Spaces
Boris Burshteyn
Based on the recently introduced uniform adjustment for closed subspaces of Banach spaces we extend the concept of the strictly singular and finitely strictly singular operator…
math.FA2008
Uniform lamda-adjustment and mu-approximation in Banach spaces
Boris Burshteyn
We introduce a new concept of perturbation of closed linear subspaces and operators in Banach spaces called uniform lambda-adjustment which is weaker than perturbations by small ga…