Results 1 to 10 of about 167 (46)
Study of the property (bz) using local spectral theory methods
Arab Journal of Basic and Applied Sciences, 2023 For a bounded linear operator, by local spectral theory methods, we study the property [Formula: see text] which means that the difference of the approximate point spectrum with the upper semi-Fredholm spectrum coincides with the set of all finite-range ...
Elvis Aponte, Jose Soto, Ennis Rosas
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Spectral Theory For Strongly Continuous Cosine
Concrete Operators, 2021 Let (C(t))t∈ℝ be a strongly continuous cosine family and A be its infinitesimal generator. In this work, we prove that, if C(t) – cosh λt is semi-Fredholm (resp.
Boua Hamid
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Limit points for descent spectrum of operator matrices
Moroccan Journal of Pure and Applied Analysis, 2022 In this paper, we investigate the limit points set of descent spectrum of upper triangular operator matrices MC=(AC0B){M_C} = \left( {\matrix{A \hfill & C \hfill \cr 0 \hfill & B \hfill \cr } } \right).
Boua H., Karmouni M., Tajmouati A.
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On (m, P)-expansive operators: products, perturbation by nilpotents, Drazin invertibility
Concrete Operators, 2021 A generalisation of m-expansive Hilbert space operators T ∈ B(ℋ) [18, 20] to Banach space operators T ∈ B(𝒳) is obtained by defining that a pair of operators A, B ∈ B(𝒳) is (m, P)-expansive for some operator P ∈ B(𝒳) if Δ A,Bm(P)= (I-LARB)m(P)=∑j=0m(-1)j(
Duggal B.P.
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A note on property (gb) and perturbations [PDF]
, 2012 An operator $T \in \mathcal{B}(X)$ defined on a Banach space $X$ satisfies property $(gb)$ if the complement in the approximate point spectrum $\sigma_{a}(T)$ of the upper semi-B-Weyl spectrum $\sigma_{SBF_{+}^{-}}(T)$ coincides with the set $\Pi(T)$ of ...
Zeng, Qingping, Zhong, Huaijie
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The random paving property for uniformly bounded matrices [PDF]
, 2007 This note presents a new proof of an important result due to Bourgain and Tzafriri that provides a partial solution to the Kadison--Singer problem. The result shows that every unit-norm matrix whose entries are relatively small in comparison with its ...
Tropp, Joel A.
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On the linear independence of spikes and sines [PDF]
, 2008 The purpose of this work is to survey what is known about the linear independence of spikes and sines. The paper provides new results for the case where the locations of the spikes and the frequencies of the sines are chosen at random.
A. Buchholz +19 more
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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
On ∗-paranormal contractions and properties for ∗-class A operators [PDF]
, 2012 An operator T∈B(H) is called a ∗-class A operator if |T2|⩾|T∗|2, and T is said to be ∗-paranormal if ‖T∗x‖2⩽‖T2x‖ for every unit vector x in H. In this paper we show that ∗-paranormal contractions are the direct sum of a unitary and a C.0 completely non ...
Duggal, Bhagwati P. +2 more
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On new strong versions of Browder type theorems
Open Mathematics, 2018 An operator T acting on a Banach space X satisfies the property (UWΠ) if σa(T)∖ σSF+−$\begin{array}{} \sigma_{SF_{+}^{-}} \end{array} $(T) = Π(T), where σa(T) is the approximate point spectrum of T, σSF+−$\begin{array}{} \sigma_{SF_{+}^{-}} \end{array} $
Sanabria José +4 more
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