Research reports by Aly A. El-Sabbagh

Here are the reports authored by Aly A. El-Sabbagh. See the reports of all authors.

Helsinki University of Technology Institute of Mathematics Research Reports A

A539: Aly A. El-Sabbagh, F.A. Abd El Salam, K. El Nagaar; On the spectrum of the symmetric relations for the canonical systems of differential equations in Hilbert space [pdf][ps] abstract: [pdf][ps]; Received 2007-12-18 * Hilbert Spaces, Symmetric Relations, minimal and maximal relations, Weyl-Coefficients, and Canonical Systems of Differential Equations * AMS 47A20 * 9 pages
A538: Aly A. El-Sabbagh, F.A. Abd El Salam, K. El Nagaar; On the existence of the selfadjoint extension of the symmetric relation in Hilbert space [pdf][ps] abstract: [pdf][ps]; Received 2007-12-18 * Symmetric Operator, Symmetric Relation, Hilbert Space, Perturbing Case, Selfadjoint Extensions, Krein Space * AMS 47A20 * 9 pages