Results 41 to 50 of about 4,674,369 (143)

Essential spectrum of systems of singular differential equations [PDF]

, 2013
In this paper we develop a new method to determine the essential spectrum of coupled systems of singular differential equations.
Langer, Heinz, Langer, Matthias, Ibrogimov, Orif, Tretter, Christiane   +3 more
core  

Compactness of the difference between the porous thermoelastic semigroup and its decoupled semigroup

Electronic Journal of Differential Equations, 2015
Under suitable assumptions, we prove the compactness of the difference between the porous thermoelastic semigroup and its decoupled one. This will be achieved by proving the norm continuity of this difference and the compactness of the difference ...
El Mustapha Ait Benhassi, Jamal Eddine Benyaich, Hammadi Bouslous, Lahcen Maniar   +3 more
doaj  

Self-Commutators of Composition Operators with Monomial Symbols on the Dirichlet Space

Abstract and Applied Analysis, 2011
Let 𝜑(𝑧)=𝑧𝑛,𝑧∈𝕌, for some positive integer 𝑛 and 𝐶𝜑 the composition operator on the Dirichlet space 𝒟 induced by 𝜑. In this paper, we completely determine the point spectrum, spectrum, essential spectrum, and essential norm of the operators 𝐶∗𝜑𝐶𝜑,𝐶𝜑𝐶∗𝜑 ...
A. Abdollahi, S. Mehrangiz
doaj   +1 more source

Essential versus $\#$-spectrum for smooth diffeomorphisms [PDF]

Proceedings of the American Mathematical Society, 1985
\textit{J. W. Robbin} conjectured in his 1972 survey article [Bull. Am. Math. Soc. 78, 923-952 (1972; Zbl 0256.58008)] that the ''essential'' and {\#}-spectra are identical for all \(C^ 1-diffeomorphisms\). If so, the stability conjecture of S. Smale follows.
openaire   +2 more sources

Essential Spectrum of a Class of Riemannian Manifolds [PDF]

The Journal of Geometric Analysis, 2014
In this paper we consider a family of Riemannian manifolds, not necessarily complete, with curvature conditions in a neighborhood of a ray. Under these conditions we obtain that the essential spectrum of the Laplacian contains an interval. The results presented in this paper allow to determine the spectrum of the Laplace operator on unlimited regions ...
Monte, Luiz Antônio C., Montenegro, José Fabio B.   +1 more
openaire   +3 more sources

Essentially alpha-hyponormal operators with essential spectrum of area zero

Le Matematiche, 2010
We prove that essentially alpha-hyponormal operators with zero area of the essential spectrum are essentially normal.
Vasile Lauric
doaj  

Spectrum, April 1981 [PDF]

, 1981
Volume 3, Number 3 of Spectrum literary journalhttps://nwcommons.nwciowa.edu/spectrum/1005/thumbnail ...
Spectrum Contributors,
core   +1 more source

Spectrum, May 1979 [PDF]

, 1979
Vol.
Spectrum Contributors,
core   +1 more source

On the eigenvalues of the lattice spin-boson model with at most one photon [PDF]

E3S Web of Conferences
In the present paper we consider a lattice spin-boson model with at most one photon A , which has a 2×2 block operator matrix representation. The essential spectrum of A is analyzed. We prove that the operator matrix A has four eigenvalues.
Dilmurodov Elyor B., Bahronov Bekzod I., Khayitova Khilola G., Kurbonov Gulomjon G., Norchayev Rustam T.   +4 more
doaj   +1 more source

Spectrum, April 1984 [PDF]

, 1984
Volume 6, Number 1 of Spectrum literary journalhttps://nwcommons.nwciowa.edu/spectrum/1010/thumbnail ...
Spectrum Contributors,
core   +1 more source