10 citations · 23 across the 7 of their papers we have counts for
8 papers · 1 filter
A geometric characterization of range-kernel complementarity
Dimosthenis Drivaliaris, Nikos Yannakakis
We show that a bounded linear operator on a Banach space with closed range has range-kernel complementarity if and only if its generalized amplitude is less than . An applicatio…
The spectrum of the restriction to an invariant subspace
Dimosthenis Drivaliaris, Nikos Yannakakis
Let be a Banach space, and be an invariant subspace of . We present an alternative proof that, if the spectrum of the restriction of to contains a po…
The angle along a curve and range-kernel complementarity
Dimosthenis Drivaliaris, Nikos Yannakakis
In this paper, we define the angle of a bounded linear operator along an unbounded path emanating from the origin and use it to characterize range-kernel complementarity. In pa…
The angle of an operator and range and kernel complementarity
Dimosthenis Drivaliaris, Nikos Yannakakis
We show that if the angle of a bounded linear operator on a Banach space, with closed range and closed sum of its range and kernel, is less than , then its range and kernel are…
Factorizations of EP operators
Dimosthenis Drivaliaris, Sotirios Karanasios, Dimitrios Pappas
In this paper we characterize EP operators through the existence of different types of factorizations. Our results extend to EP operators existing characterizations for EP matrices…
Hilbert space structure and positive operators
D. Drivaliaris, N. Yannakakis
Let X be a real Banach space. We prove that the existence of an injective, positive, symmetric and not strictly singular operator from X into its dual implies that either X admits…