Results 41 to 50 of about 1,463 (129)
Sequences of bounds for the spectral radius of a positive operator
, 2019 In 1992, Szyld provided a sequence of lower bounds for the spectral radius of a nonnegative matrix $A$, based on the geometric symmetrization of powers of $A$.
Drnovšek, Roman
core +1 more source
Left and right generalized Drazin invertible operators on Banach spaces and applications
Operators and Matrices, 2019 In this paper, left and right generalized Drazin invertible operators on Banach spaces are defined and characterized by means of the generalized Kato decomposition. Then, new binary relations associated with these operators are presented and studied.
D. E. Ferreyra, F. Levis, N. Thome
semanticscholar +1 more source
On the largest analytic set for cyclic operators
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 30, Page 1899-1909, 2003., 2003 We describe the set of analytic bounded point evaluations for an arbitrary cyclic bounded linear operator T on a Hilbert space ℋ; some related consequences are discussed. Furthermore, we show that two densely similar cyclic Banach‐space operators possessing Bishop′s property (β) have equal approximate point spectra.
A. Bourhim
wiley +1 more source
Common fixed point theorems for a pair of countably condensing mappings in ordered banach spaces
International Journal of Stochastic Analysis, Volume 16, Issue 3, Page 243-248, 2003., 2003 In this paper some common fixed point theorems for a pair of multivalued weakly isotone mappings on an ordered Banach space are proved.
B. C. Dhage +2 more
wiley +1 more source
Resolvent convergence of Sturm-Liouville operators with singular potentials
, 2010 In this paper we consider the Sturm-Liuoville operator in the Hilbert space $L_2$ with the singular complex potential of $W^{-1}_2$ and two-point boundary conditions. For this operator we give sufficient conditions for norm resolvent approximation by the
A. M. Savchuk +6 more
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Spectral integration and spectral theory for non‐Archimedean Banach spaces
International Journal of Mathematics and Mathematical Sciences, Volume 31, Issue 7, Page 421-442, 2002., 2002 Banach algebras over arbitrary complete non‐Archimedean fields are considered such that operators may be nonanalytic. There are different types of Banach spaces over non‐Archimedean fields. We have determined the spectrum of some closed commutative subalgebras of the Banach algebra ℒ(E) of the continuous linear operators on a free Banach space E ...
S. Ludkovsky, B. Diarra
wiley +1 more source
Negative Powers of Contractions Having a Strong AA+ Spectrum
Moroccan Journal of Pure and Applied Analysis, 2023 Zarrabi proved in 1993 that if the spectrum of a contraction T on a Banach space is a countable subset of the unit circle 𝕋, and if limn→+∞log(‖T−n‖)n=0{\lim _{n \to + \infty }}{{\log \left( {\left\| {{T^{ - n}}} \right\|} \right)} \over {\sqrt n ...
Esterle Jean
doaj +1 more source
Generalized Derivations and Norm Equality in Normed Ideals [PDF]
, 2011 2000 Mathematics Subject Classification: 47A10, 47A12, 47A30, 47B10, 47B20, 47B37, 47B47, 47D50.We compare the norm of a generalized derivation on a Hilbert space with the norm of its restrictions to Schatten norm ...
Barraa, Mohamed
core
Exponentials of Normal Operators and Commutativity of Operators: A New Approach
, 2011 We present a new approach to the question of when the commutativity of operator exponentials implies that of the operators. This is proved in the setting of bounded normal operators on a complex Hilbert space.
Mortad, Mohammed Hichem
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Operators with minimal pseudospectra and connections to normality
, 2020 This paper mainly studies the class of bounded linear operators A with minimal pseudospectra σε (A) = σ(A)+Dε for some ε > 0 , where σ(A) denotes the spectrum of A , and Dε denotes the open disk of radius ε centered at the origin.
Samir Raouafi
semanticscholar +1 more source