Upper triangular operator matrices and limit points of the essential spectrum

Resumen

In this paper, we investigate the limit points set of essential spectrum of upper triangular operator matrices We prove that accσe(MC) ∪ W = accσe(A) ∪ accσe(B) where W is the union of certain holes in accσe(MC), which happen to be subsets of accσe(B) ∩ accσe(A). Also, several sufficient conditions for accσe(MC) = accσe(A) ∪ accσe(B) holds are given.

Biografía del autor/a

Mohammed Karmouni, Cadi Ayyad University.
Department of Mathematics and Computer Science, Faculty Polydisciplinary of Safi.
A. Tajmouati, Sidi Mohamed Ben Abdellah University.
Faculty of Sciences Dhar Al Mahraz, Laboratory of Mathematical Analysis and Applications.
A. A. El Bakkali, Chouaib Doukkali University.
Faculty of Science, Department of Mathematics.

Citas

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Publicado
2019-08-06
Cómo citar
[1]
M. Karmouni, A. Tajmouati, y A. A. El Bakkali, «Upper triangular operator matrices and limit points of the essential spectrum», Proyecciones (Antofagasta, En línea), vol. 38, n.º 3, pp. 401-409, ago. 2019.
Sección
Artículos