On the spectra of non‐selfadjoint differential operators and their adjoints in direct sum spaces
Sobhy El-Sayed IbrahimDepartment of Mathematics, Faculty of Science, Benha University, Kalubia, Benha 13518, Egypt
2003en
ABI
Abstract
The general ordinary quasidifferential expression M p of n th order, with complex coefficients and its formal adjoint on any finite number of intervals I p = ( a p , b p ), p = 1, …, N , are considered in the setting of the direct sums of ‐spaces of functions defined on each of the separate intervals. And a number of results concerning the location of the point spectra and regularity fields of general differential operators generated by such expressions are obtained.
Identifiers
Citations and references
Cited by 30 references