Fedotov, Alexander; Shchetka, Ekaterina Difference equations in the complex plane: quasiclassical asymptotics and Berry phase. (English) Zbl 1484.39018 Appl. Anal. 101, No. 1, 274-296 (2022). MSC: 39A45 PDFBibTeX XMLCite \textit{A. Fedotov} and \textit{E. Shchetka}, Appl. Anal. 101, No. 1, 274--296 (2022; Zbl 1484.39018) Full Text: DOI arXiv
Fedotov, A.; Shchetka, E. The spectrum and density of states of the almost Mathieu operator with frequency represented by a continued fraction with large elements. (English. Russian original) Zbl 07215619 Math. Notes 107, No. 6, 1040-1045 (2020); translation from Mat. Zametki 107, No. 6, 648-953 (2020). MSC: 47Bxx 47Axx PDFBibTeX XMLCite \textit{A. Fedotov} and \textit{E. Shchetka}, Math. Notes 107, No. 6, 1040--1045 (2020; Zbl 07215619); translation from Mat. Zametki 107, No. 6, 648--953 (2020) Full Text: DOI
Fedotov, A.; Shchetka, E. Complex WKB method for a difference Schrödinger equation with the potential being a trigonometric polynomial. (English. Russian original) Zbl 1385.39001 St. Petersbg. Math. J. 29, No. 2, 363-381 (2018); translation from Algebra Anal. 29, No. 2, 193-219 (2017). MSC: 39A12 34E20 34L40 39A22 PDFBibTeX XMLCite \textit{A. Fedotov} and \textit{E. Shchetka}, St. Petersbg. Math. J. 29, No. 2, 363--381 (2018; Zbl 1385.39001); translation from Algebra Anal. 29, No. 2, 193--219 (2017) Full Text: DOI