Results 61 to 70 of about 822,201 (162)

Hyponormal Operators with Infinite Essential Spectrum [PDF]

Proceedings of the American Mathematical Society, 1975
It is shown that if T T is an essentially hyponormal operator (i.e., the image of
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A New Stability of the S-Essential Spectrum of Multivalued Linear Operators

International Journal of Analysis and Applications, 2017
We unfold in this paper two main results. In the first, we give the necessary assumptions for three linear relations $A$, $B$ and $S$ such that $\sigma_{eap,S}(A+B)= \sigma _{eap,S}(A)$ and $\sigma_{e\delta,S}(A+B)= \sigma_{e\delta,S}(A)$ is true. In the
Aymen Ammar, Slim Fakhfakh, Aref Jeribi
doaj   +2 more sources

Broad-Spectrum Antimicrobial Activity of Thymus Zygis Essential Oil Against Various Microorganisms

Journal of Agricultural Sciences
In this study, the antimicrobial effect of the T. zygis essential oil (EO) was investigated on 68 bacterial and two yeast isolates belonging to 20 different families, including foodborne, ready-to-eat food, aquatic, and collection strains that are ...
Dilek Kahraman Yılmaz
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Essential Self-Adjointness and Invariance of the Essential Spectrum for Dirac Operators

Publications of the Research Institute for Mathematical Sciences, 1982
where «_,(j = 1, 2, 3) and a4 = /? are Hermitian symmetric, constant, 4x4 matrices and satisfy the anti-commutation relations (U) aLjQik + aikaij = 2djkI (/, k = l, 2, 3, 4) (/ is the 4x4 unit matrix). Throughout this paper the potential Q(x) is assumed to be an Hermitian symmetric 4x4 matrix-valued measurable function. The Dirac operator is treated in
Arai, Masaharu, Yamada, Osanobu
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The Birman–Schwinger principle on the essential spectrum

Journal of Functional Analysis, 2011
Let $H_0$ and $H$ be self-adjoint operators in a Hilbert space. We consider the spectral projections of $H_0$ and $H$ corresponding to a semi-infinite interval of the real line. We discuss the index of this pair of spectral projections and prove an identity which extends the Birman-Schwinger principle onto the essential spectrum.
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Discontinuities Cause Essential Spectrum on Surfaces

Annales Henri Poincaré
Abstract Two-dimensional maps with discontinuities are considered. It is shown that, in the presence of discontinuities, the essential spectrum of the transfer operator is large whenever it acts on a Banach space with norm that is stronger than $$L^\infty $$
BUTTERLEY, Oliver James, Canestrari, Giovanni, CASTORRINI, Roberto   +2 more
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The Essential Spectrum of the Laplacian on Manifolds with Ends

Publications of the Research Institute for Mathematical Sciences, 2009
Let V be a noncompact complete Riemannian manifold. We find a geometric condition which assures that the essential spectrum of the Laplacian on V contains a half-line, by means of fiber bundle structures and the asymptotic behavior of mean curvatures on
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A Note on Bifurcation from the Essential Spectrum

Advanced Nonlinear Studies, 2003
Abstract In this paper we study a semilinear elliptic equation in all ℝ N . This equation depends on a parameter λ, and we obtain, for small λ < 0, solutins which are small in H 1 (ℝ N ).
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Quasi-Compact Perturbations of the Weyl Essential Spectrum and Application to Singular Transport Operators

International Journal of Analysis and Applications, 2015
This paper is devoted to the investigation of the stability of the Weyl essential spectrum of closed densely dened linear operator A subjected to additive perturbation K such that (lambda-A-K)^{-1}K or K(lambda-A-K)^{-1} is a quasi-compact operator ...
Leila Mebarki, Mohammed Benharrat, Bekkai Messirdi   +2 more
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On the essential spectrum

Journal of Mathematical Analysis and Applications, 1969
Gustafson, K, Weidmann, J
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