Messirdi, Sofiane; Messirdi, Sanaa; Messirdi, Bekkai New characterizations of left and right generalized Drazin invertible bounded operators. (English) Zbl 1484.47003 An. Univ. Oradea, Fasc. Mat. 27, No. 2, 55-59 (2020). MSC: 47A05 47A10 PDFBibTeX XMLCite \textit{S. Messirdi} et al., An. Univ. Oradea, Fasc. Mat. 27, No. 2, 55--59 (2020; Zbl 1484.47003)
Belmouhoub, Soumia; Messirdi, Bekkai Singular Schrödinger operators via Grushin problem method. (English) Zbl 1389.81020 An. Univ. Oradea, Fasc. Mat. 24, No. 1, 83-91 (2017). MSC: 81Q10 35S05 PDFBibTeX XMLCite \textit{S. Belmouhoub} and \textit{B. Messirdi}, An. Univ. Oradea, Fasc. Mat. 24, No. 1, 83--91 (2017; Zbl 1389.81020)
Benharrat, Mohammed; Messirdi, Bekkai Relationship between the essential quasi-Fredholm spectrum and the closed-range spectrum. (English) Zbl 1313.47010 An. Univ. Oradea, Fasc. Mat. 21, No. 1, 5-12 (2014). MSC: 47A10 47A53 PDFBibTeX XMLCite \textit{M. Benharrat} and \textit{B. Messirdi}, An. Univ. Oradea, Fasc. Mat. 21, No. 1, 5--12 (2014; Zbl 1313.47010)