Results 1 to 10 of about 27 (27)

Study of the property (bz) using local spectral theory methods

open access: yesArab 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
doaj   +1 more source

Spectral Theory For Strongly Continuous Cosine

open access: yesConcrete 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
doaj   +1 more source

Limit points for descent spectrum of operator matrices

open access: yesMoroccan 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.
doaj   +1 more source

On (m, P)-expansive operators: products, perturbation by nilpotents, Drazin invertibility

open access: yesConcrete 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.
doaj   +1 more source

On the largest analytic set for cyclic operators

open access: yesInternational 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 new strong versions of Browder type theorems

open access: yesOpen 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
doaj   +1 more source

Early warning signs for SPDEs with continuous spectrum

open access: yesEuropean Journal of Applied Mathematics
In this work, we study early warning signs for stochastic partial differential equations (SPDEs), where the linearisation around a steady state is characterised by continuous spectrum. The studied warning sign takes the form of qualitative changes in the
Paolo Bernuzzi   +2 more
doaj   +1 more source

Static spectra and static families of Fredholm-type operators under tensor product

open access: yesArab Journal of Basic and Applied Sciences
In this study, we introduce the static spectrum, the Weyl static families, the upper semi-Fredholm static families, and the Browder static families. These families consist of bounded linear operators parameterized by a scalar variable.
Elvis Aponte
doaj   +1 more source

Nilpotent perturbations of m-isometric and m-symmetric tensor products of commuting d-tuples of operators

open access: yesDemonstratio Mathematica
If T1{{\mathbb{T}}}_{1} and T2{{\mathbb{T}}}_{2} are commuting dd-tuples of Hilbert space operators in B(ℋ)dB{\left({\mathcal{ {\mathcal H} }})}^{d} such that (T1*⊗I+I⊗T2*,T1⊗I+I⊗T2)\left({{\mathbb{T}}}_{1}^{* }\otimes I+I\otimes {{\mathbb{T}}}_{2}^{* },{
Duggal Bhagwati Prashad, Kim In Hyoun
doaj   +1 more source

The mitotic regulator polo-like kinase 1 as a potential therapeutic target for c-Myc-overexpressing canine osteosarcomas. [PDF]

open access: yesVet Comp Oncol, 2022
Gola C   +8 more
europepmc   +1 more source

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