Results 21 to 30 of about 141 (138)

A formula for the inner spectral radius

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 61, Page 3285-3290, 2004., 2004
This note presents an asymptotic formula for the minimum of the moduli of the elements in the spectrum of a bounded linear operator acting on Banach space X. This minimum moduli is called the inner spectral radius, and the formula established herein is an analogue of Gelfand′s spectral radius formula.
S. Mahmoud Manjegani
wiley   +1 more source

Almost Jordan homomorphisms on Fréchet algebras [PDF]

open access: yes, 2021
In this paper we study the notation of almost Jordan homomorphism between Fréchet algebras. We show that if (A; (pn)) is a Fréchet algebra and T : A → ℂ is a almost Jordan homomorphism, then either T is homomorphism, or it is continuous.
Zivari-Kazempour, A.   +2 more
core  

Spectrum perturbations of compact operators in a Banach space

open access: yesOpen Mathematics, 2019
For an integer p ≥ 1, let Γp be an approximative quasi-normed ideal of compact operators in a Banach space with a quasi-norm NΓp(.) and the ...
Gil’ Michael
doaj   +1 more source

Structure of n-quasi left m-invertible and related classes of operators

open access: yesDemonstratio Mathematica, 2020
Given Hilbert space operators T,S∈B(ℋ)T,S\in B( {\mathcal H} ), let Δ\text{Δ} and δ∈B(B(ℋ))\delta \in B(B( {\mathcal H} )) denote the elementary operators ΔT,S(X)=(LTRS−I)(X)=TXS−X{\text{Δ}}_{T,S}(X)=({L}_{T}{R}_{S}-I)(X)=TXS-X and δT,S(X)=(
Duggal Bhagwati Prashad, Kim In Hyun
doaj   +1 more source

Spectral analysis for a class of integral‐difference operators: known facts, new results, and open problems

open access: yesDiscrete Dynamics in Nature and Society, Volume 2004, Issue 1, Page 221-249, 2004., 2004
We present state of the art, the new results, and discuss open problems in the field of spectral analysis for a class of integral‐difference operators appearing in some nonequilibrium statistical physics models as collision operators. The author dedicates this work to the memory of Professor Ilya Prigogine, who initiated this activity in 1997 and ...
Yuri B. Melnikov
wiley   +1 more source

Functional analysis method for the M/G/1 queueing model with single working vacation

open access: yesOpen Mathematics, 2018
In this paper, we study the asymptotic property of underlying operator corresponding to the M/G/1 queueing model with single working vacation, where both service times in a regular busy period and in a working vacation period are function. We obtain that
Kasim Ehmet, Gupur Geni
doaj   +1 more source

Essential 𝒰cκ‐type maps and Birkhoff‐Kellogg theorems

open access: yesInternational Journal of Stochastic Analysis, Volume 2004, Issue 1, Page 1-8, 2004., 2004
We present a new continuation theorem for 𝒰cκ‐type maps. The analysis is elementary and relies on properties of retractions and fixed point theory for self‐maps. Also we present some Birkhoff‐Kellogg type theorems on invariant directions.
R. P. Agarwal, Donal O′Regan
wiley   +1 more source

Generalized lower characteristic involving measures of non-strict singularity

open access: yesTopological Algebra and its Applications, 2023
This work establishes a connection between the class of generalized lower characteristic operators and [⋅]a{\left[\cdot ]}_{a} acting on a Banach space involving measures of non-strict singularity.
Baraket Sami   +2 more
doaj   +1 more source

Local spectral theory for 2 × 2 operator matrices

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 42, Page 2667-2672, 2003., 2003
We discuss the spectral properties of the operator MC ∈ ℒ(X ⊕ Y) defined by MC:=(AC0B), where A ∈ ℒ(X), B ∈ ℒ(Y), C ∈ ℒ(Y, X), and X, Y are complex Banach spaces. We prove that (SA∗∩SB)∪σ(MC)=σ(A)∪σ(B) for all C ∈ ℒ(Y, X). This allows us to give a partial positive answer to Question 3 of Du and Jin (1994) and generalizations of some results of Houimdi ...
H. Elbjaoui, E. H. Zerouali
wiley   +1 more source

Eigenvalue bracketing for discrete and metric graphs [PDF]

open access: yes, 2008
28 pages, 6 figures.-- MSC2000 codes: 05C50, 05C70, 47A10.-- ArXiv pre-print available at: http://arxiv.org/abs/0804.1076MR#: MR2446037 (2010a:47076)Zbl#: Zbl 1152.05044We develop eigenvalue estimates for the Laplacians on discrete and metric graphs ...
Post, Olaf   +4 more
core   +1 more source

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