Results 21 to 30 of about 141 (138)
On some properties of Banach operators. II
International Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 47, Page 2513-2515, 2004., 2004 Using the notion of a Banach operator, wehave obtained a decompositional property of aHilbert space, and the equality of two invertible boundedlinear multiplicative operators on a normed algebra with identity.
A. B. Thaheem, A. R. Khan
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A formula for the inner spectral radius
International 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
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Discrete 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
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Essential 𝒰cκ‐type maps and Birkhoff‐Kellogg theorems
International 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
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Generalized lower characteristic involving measures of non-strict singularity
Topological 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
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Local spectral theory for 2 × 2 operator matrices
International 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
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Eigenvalue bracketing for discrete and metric graphs [PDF]
, 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
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Spectral inclusions and stability results for strongly continuous semigroups
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 37, Page 2379-2387, 2003., 2003 We prove some spectral inclusions for strongly continuous semigroups. Some stability results are also established.
Abdelkader Elkoutri, Mohamed Aziz Taoudi
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The spectrum of a class of almost periodic operators
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 36, Page 2277-2301, 2003., 2003 For almost Mathieu operators, it is shown that the occurrence of Cantor spectrum and the existence, for every point in the spectrum and suitable phase parameters, of at least one localized eigenfunction which decays exponentially are inconsistent properties.
Norbert Riedel
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On the completely indeterminate case for block Jacobi matrices
Concrete Operators, 2017 We consider the infinite Jacobi block matrices in the completely indeterminate case, i. e. such that the deficiency indices of the corresponding Jacobi operators are maximal.
Osipov Andrey
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