In this paper, spectral analysis of infinite triangular double-band matrices acting as operators on the Cesàro space σ_0 is given. The study includes a detailed analysis of the spectrum, distinguishing between different types of the spectrum (e.g., point spectrum, residual spectrum, continuous spectrum, defect spectrum, compression spectrum and approximate point spectrum). Besides, a finer subdivision of the spectrum is given. A generalization of the study to symmetric and non-symmetric tridiagonal matrices is also derived. The technique used in this study is flexible enough to address the spectral problem of the underlying operators in various sequence spaces.
El-Ashwah, R., El-Morshedy, H., Shindy, A., & El-Shabrawy, S. (2025). On the spectra of some infinite band matrices as operators on the Cesàro sequence space σ_0. Scientific Journal for Damietta Faculty of Science, 15(2), 212-225. doi: 10.21608/sjdfs.2025.405831.1253
MLA
Rabha M. El-Ashwah; H. A. El-Morshedy; Asmaa M. Shindy; Saad R. El-Shabrawy. "On the spectra of some infinite band matrices as operators on the Cesàro sequence space σ_0", Scientific Journal for Damietta Faculty of Science, 15, 2, 2025, 212-225. doi: 10.21608/sjdfs.2025.405831.1253
HARVARD
El-Ashwah, R., El-Morshedy, H., Shindy, A., El-Shabrawy, S. (2025). 'On the spectra of some infinite band matrices as operators on the Cesàro sequence space σ_0', Scientific Journal for Damietta Faculty of Science, 15(2), pp. 212-225. doi: 10.21608/sjdfs.2025.405831.1253
VANCOUVER
El-Ashwah, R., El-Morshedy, H., Shindy, A., El-Shabrawy, S. On the spectra of some infinite band matrices as operators on the Cesàro sequence space σ_0. Scientific Journal for Damietta Faculty of Science, 2025; 15(2): 212-225. doi: 10.21608/sjdfs.2025.405831.1253
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