Nhi Pham; Spitkovsky, Ilya M. On 3-by-3 row stochastic matrices. (English) Zbl 1525.15026 Spec. Matrices 11, Article ID 20230103, 14 p. (2023). MSC: 15B51 PDFBibTeX XMLCite \textit{Nhi Pham} and \textit{I. M. Spitkovsky}, Spec. Matrices 11, Article ID 20230103, 14 p. (2023; Zbl 1525.15026) Full Text: DOI OA License
Böttcher, Albrecht; Spitkovsky, Ilya M. Core invertibility of operators from the algebra generated by two orthogonal projections. (English) Zbl 07722765 Acta Sci. Math. 89, No. 1-2, 257-268 (2023). MSC: 47C15 15A09 47A05 47L15 PDFBibTeX XMLCite \textit{A. Böttcher} and \textit{I. M. Spitkovsky}, Acta Sci. Math. 89, No. 1--2, 257--268 (2023; Zbl 07722765) Full Text: DOI
Johnson, Charles; Newman, Stephen; Spitkovsky, Ilya New views of the doubly stochastic single eigenvalue problem. (English) Zbl 1518.15012 Linear Multilinear Algebra 71, No. 9, 1462-1469 (2023). MSC: 15A18 15B51 PDFBibTeX XMLCite \textit{C. Johnson} et al., Linear Multilinear Algebra 71, No. 9, 1462--1469 (2023; Zbl 1518.15012) Full Text: DOI
He, Qixiao; Spitkovsky, Ilya; Suleiman, Ibrahim On low-dimensional partial isometries. (English) Zbl 1515.15023 Electron. J. Linear Algebra 39, 124-135 (2023). MSC: 15A60 47A12 PDFBibTeX XMLCite \textit{Q. He} et al., Electron. J. Linear Algebra 39, 124--135 (2023; Zbl 1515.15023) Full Text: arXiv Link
Ephremidze, Lasha; Mishuris, Gennady; Spitkovsky, Ilya On the exact spectral factorization of rational matrix functions with applications to paraunitary filter banks. arXiv:2312.03518 Preprint, arXiv:2312.03518 [math.CV] (2023). MSC: 47A68 65T60 15A83 BibTeX Cite \textit{L. Ephremidze} et al., ``On the exact spectral factorization of rational matrix functions with applications to paraunitary filter banks'', Preprint, arXiv:2312.03518 [math.CV] (2023) Full Text: arXiv OA License
Ephremidze, Lasha; Saatashvili, Aleksandre; Spitkovsky, Ilya M. On \(j\)-unitary matrix polynomials. (English) Zbl 07798357 J. Math. Sci., New York 266, No. 1, Series A, 196-209 (2022). MSC: 47Axx 42Cxx 15Axx PDFBibTeX XMLCite \textit{L. Ephremidze} et al., J. Math. Sci., New York 266, No. 1, 196--209 (2022; Zbl 07798357) Full Text: DOI
Ephremidze, Lasha; Gamkrelidze, Alexander; Spitkovsky, Ilya On the spectral factorization of singular, noisy, and large matrices by Janashia-Lagvilava method. (English) Zbl 07740729 Trans. A. Razmadze Math. Inst. 176, No. 3, 361-366 (2022). Reviewer: Bahar Arslan (Bursa) MSC: 47A68 15A23 65Y15 PDFBibTeX XMLCite \textit{L. Ephremidze} et al., Trans. A. Razmadze Math. Inst. 176, No. 3, 361--366 (2022; Zbl 07740729) Full Text: Link
Poon, Edward; Spitkovsky, Ilya M.; Woerdeman, Hugo J. Factorization of singular matrix polynomials and matrices with circular higher rank numerical ranges. (English) Zbl 07579346 SIAM J. Matrix Anal. Appl. 43, No. 3, 1423-1439 (2022). MSC: 47A68 47A56 15A23 15A60 47A12 PDFBibTeX XMLCite \textit{E. Poon} et al., SIAM J. Matrix Anal. Appl. 43, No. 3, 1423--1439 (2022; Zbl 07579346) Full Text: DOI
Ephremidze, Lasha; Spitkovsky, Ilya M. On multivariable matrix spectral factorization method. (English) Zbl 1507.47044 J. Math. Anal. Appl. 514, No. 1, Article ID 126300, 25 p. (2022). Reviewer: Adhemar Bultheel (Leuven) MSC: 47A68 15A69 93B28 PDFBibTeX XMLCite \textit{L. Ephremidze} and \textit{I. M. Spitkovsky}, J. Math. Anal. Appl. 514, No. 1, Article ID 126300, 25 p. (2022; Zbl 1507.47044) Full Text: DOI arXiv
Camenga, Kristin A.; Rault, Patrick X.; Spitkovsky, Ilya M.; Yates, Rebekah B. Johnson The Gau-Wu number for \(4 \times 4\) and select arrowhead matrices. (English) Zbl 1487.15028 Linear Algebra Appl. 644, 192-218 (2022). MSC: 15A60 15A18 15B57 47A12 PDFBibTeX XMLCite \textit{K. A. Camenga} et al., Linear Algebra Appl. 644, 192--218 (2022; Zbl 1487.15028) Full Text: DOI arXiv
Jiang, Muyan; Spitkovsky, Ilya M. On some reciprocal matrices with elliptical components of their Kippenhahn curves. (English) Zbl 1514.15030 Spec. Matrices 10, 117-130 (2022). MSC: 15A60 14H50 47A12 47B36 PDFBibTeX XMLCite \textit{M. Jiang} and \textit{I. M. Spitkovsky}, Spec. Matrices 10, 117--130 (2022; Zbl 1514.15030) Full Text: DOI arXiv
Spitkovsky, Ilya; Suleiman, Ibrahim; Wegert, Elias The Gau-Wang-Wu conjecture on partial isometries holds in the 5-by-5 case. (English) Zbl 07473282 Electron. J. Linear Algebra 38, 107-113 (2022). Reviewer: Tin Yau Tam (Reno) MSC: 47A12 15A60 PDFBibTeX XMLCite \textit{I. Spitkovsky} et al., Electron. J. Linear Algebra 38, 107--113 (2022; Zbl 07473282) Full Text: arXiv Link
Quartz, Thanin; Spitkovsky, Ilya M. On the Stampfli point of some operators and matrices. (English) Zbl 1506.47010 Oper. Matrices 15, No. 4, 1267-1287 (2021). MSC: 47A12 47A08 47B20 15A60 PDFBibTeX XMLCite \textit{T. Quartz} and \textit{I. M. Spitkovsky}, Oper. Matrices 15, No. 4, 1267--1287 (2021; Zbl 1506.47010) Full Text: DOI arXiv
Wegert, Elias; Spitkovsky, Ilya On partial isometries with circular numerical range. (English) Zbl 07454938 Concr. Oper. 8, 176-186 (2021). Reviewer: Mikhail Tyaglov (Shanghai) MSC: 47A12 15A60 30J10 33E05 51M15 PDFBibTeX XMLCite \textit{E. Wegert} and \textit{I. Spitkovsky}, Concr. Oper. 8, 176--186 (2021; Zbl 07454938) Full Text: DOI arXiv
Cox, Mackenzie; Grewe, Weston; Hochrein, Grace; Patton, Linda; Spitkovsky, Ilya Nonparallel flat portions on the boundaries of numerical ranges of 4-by-4 nilpotent matrices. (English) Zbl 1475.15025 Electron. J. Linear Algebra 37, 504-523 (2021). MSC: 15A60 47A12 PDFBibTeX XMLCite \textit{M. Cox} et al., Electron. J. Linear Algebra 37, 504--523 (2021; Zbl 1475.15025) Full Text: arXiv Link
Bebiano, Natália; da Providéncia, Joáo; Spitkovsky, Ilya M. On Kippenhahn curves and higher-rank numerical ranges of some matrices. (English) Zbl 1478.15031 Linear Algebra Appl. 629, 246-257 (2021). Reviewer: Agnes Radl (Berlin) MSC: 15A60 47A12 PDFBibTeX XMLCite \textit{N. Bebiano} et al., Linear Algebra Appl. 629, 246--257 (2021; Zbl 1478.15031) Full Text: DOI arXiv
Geryba, Titas; Spitkovsky, Ilya M. On some 4-by-4 matrices with bi-elliptical numerical ranges. (English) Zbl 1473.15027 Linear Multilinear Algebra 69, No. 5, 855-870 (2021). Reviewer: Farida Lombarkia (Batna) MSC: 15A60 15A21 47A12 PDFBibTeX XMLCite \textit{T. Geryba} and \textit{I. M. Spitkovsky}, Linear Multilinear Algebra 69, No. 5, 855--870 (2021; Zbl 1473.15027) Full Text: DOI arXiv
Geryba, Titas; Spitkovsky, Ilya M. On the numerical range of some block matrices with scalar diagonal blocks. (English) Zbl 1462.15027 Linear Multilinear Algebra 69, No. 5, 772-785 (2021). MSC: 15A60 47A12 PDFBibTeX XMLCite \textit{T. Geryba} and \textit{I. M. Spitkovsky}, Linear Multilinear Algebra 69, No. 5, 772--785 (2021; Zbl 1462.15027) Full Text: DOI arXiv
Ephremidze, L.; Spitkovsky, I. On explicit Wiener-Hopf factorization of \(2 \times 2\) matrices in a vicinity of a given matrix. (English) Zbl 1472.15020 Proc. R. Soc. Lond., A, Math. Phys. Eng. Sci. 476, No. 2238, Article ID 20200027, 12 p. (2020). MSC: 15A23 65F99 PDFBibTeX XMLCite \textit{L. Ephremidze} and \textit{I. Spitkovsky}, Proc. R. Soc. Lond., A, Math. Phys. Eng. Sci. 476, No. 2238, Article ID 20200027, 12 p. (2020; Zbl 1472.15020) Full Text: DOI
Bebiano, Natália; da Providéncia, Joáo; Spitkovsky, Ilya M.; Vazquez, Kenya Kippenhahn curves of some tridiagonal matrices. arXiv:2011.00849 Preprint, arXiv:2011.00849 [math.FA] (2020). MSC: 15A60 47A12 14H50 BibTeX Cite \textit{N. Bebiano} et al., ``Kippenhahn curves of some tridiagonal matrices'', Preprint, arXiv:2011.00849 [math.FA] (2020) Full Text: arXiv OA License
Ephremidze, Lasha; Salia, Nika; Spitkovsky, Ilya On a parametrization of non-compact wavelet matrices by Wiener-Hopf factorization. (English) Zbl 1456.15038 Trans. A. Razmadze Math. Inst. 173, No. 3, 31-36 (2019). MSC: 15B57 15A23 42C40 65T60 PDFBibTeX XMLCite \textit{L. Ephremidze} et al., Trans. A. Razmadze Math. Inst. 173, No. 3, 31--36 (2019; Zbl 1456.15038) Full Text: Link
Camenga, Kristin A.; Deaett, Louis; Rault, Patrick X.; Sendova, Tsvetanka; Spitkovsky, Ilya M.; Yates, Rebekah B. Johnson Singularities of base polynomials and Gau-Wu numbers. (English) Zbl 1423.15020 Linear Algebra Appl. 581, 112-127 (2019). Reviewer: Mohammad Sal Moslehian (Mashhad) MSC: 15A60 14H45 PDFBibTeX XMLCite \textit{K. A. Camenga} et al., Linear Algebra Appl. 581, 112--127 (2019; Zbl 1423.15020) Full Text: DOI arXiv
Hamed, Ali N.; Spitkovsky, Ilya M. On the maximal numerical range of some matrices. (English) Zbl 1398.15021 Electron. J. Linear Algebra 34, 288-303 (2018). MSC: 15A60 PDFBibTeX XMLCite \textit{A. N. Hamed} and \textit{I. M. Spitkovsky}, Electron. J. Linear Algebra 34, 288--303 (2018; Zbl 1398.15021)
Spitkovsky, Ilya M.; Voronin, Anatoly F. A note on the factorization of some structured matrix functions. (English) Zbl 1512.47033 Integral Equations Oper. Theory 90, No. 3, Paper No. 39, 7 p. (2018). MSC: 47A68 30H15 15A60 47B35 PDFBibTeX XMLCite \textit{I. M. Spitkovsky} and \textit{A. F. Voronin}, Integral Equations Oper. Theory 90, No. 3, Paper No. 39, 7 p. (2018; Zbl 1512.47033) Full Text: DOI arXiv
Ephremidze, Lasha; Saied, Faisal; Spitkovsky, Ilya Matvey On the algorithmization of Janashia-Lagvilava matrix spectral factorization method. (English) Zbl 1392.65092 IEEE Trans. Inf. Theory 64, No. 2, 728-737 (2018). MSC: 65F15 15A23 94A12 PDFBibTeX XMLCite \textit{L. Ephremidze} et al., IEEE Trans. Inf. Theory 64, No. 2, 728--737 (2018; Zbl 1392.65092) Full Text: DOI arXiv
Adam, Maria; Aretaki, Aikaterini; Spitkovsky, Ilya M. Elliptical higher rank numerical range of some Toeplitz matrices. (English) Zbl 1386.15043 Linear Algebra Appl. 549, 256-275 (2018). MSC: 15A60 15B05 81P45 81P68 81P70 PDFBibTeX XMLCite \textit{M. Adam} et al., Linear Algebra Appl. 549, 256--275 (2018; Zbl 1386.15043) Full Text: DOI
Lins, Brian; Spitkovsky, Ilya M.; Zhong, Siyu The normalized numerical range and the Davis-Wielandt shell. (English) Zbl 1391.15076 Linear Algebra Appl. 546, 187-209 (2018). MSC: 15A60 47A12 47B15 PDFBibTeX XMLCite \textit{B. Lins} et al., Linear Algebra Appl. 546, 187--209 (2018; Zbl 1391.15076) Full Text: DOI arXiv
Militzer, Erin; Patton, Linda J.; Spitkovsky, Ilya M.; Tsai, Ming-Cheng Numerical ranges of 4-by-4 nilpotent matrices: flat portions on the boundary. (English) Zbl 1365.15031 Bini, Dario A. (ed.) et al., Large truncated Toeplitz matrices, Toeplitz operators, and related topics. The Albrecht Böttcher anniversary volume. Basel: Birkhäuser/Springer (ISBN 978-3-319-49180-6/hbk; 978-3-319-49182-0/ebook). Operator Theory: Advances and Applications 259, 561-591 (2017). MSC: 15A60 47A12 PDFBibTeX XMLCite \textit{E. Militzer} et al., Oper. Theory: Adv. Appl. 259, 561--591 (2017; Zbl 1365.15031) Full Text: DOI arXiv
Spitkovsky, Ilya M.; Stoica, Andrei-Florian On the normalized numerical range. (English) Zbl 1369.15013 Oper. Matrices 11, No. 1, 219-240 (2017). Reviewer: Jorma K. Merikoski (Tampere) MSC: 15A60 47A12 47B15 PDFBibTeX XMLCite \textit{I. M. Spitkovsky} and \textit{A.-F. Stoica}, Oper. Matrices 11, No. 1, 219--240 (2017; Zbl 1369.15013) Full Text: DOI
Bini, Dario A. (ed.); Ehrhardt, Torsten (ed.); Karlovich, Alexei Yu (ed.); Spitkovsky, Ilya (ed.) Large truncated Toeplitz matrices, Toeplitz operators, and related topics. The Albrecht Böttcher anniversary volume. (English) Zbl 1367.47005 Operator Theory: Advances and Applications 259. Basel: Birkhäuser/Springer (ISBN 978-3-319-49180-6/hbk; 978-3-319-49182-0/ebook). xxvi, 740 p. (2017). MSC: 47-06 15B05 47B35 60B20 00B15 00B30 PDFBibTeX XMLCite \textit{D. A. Bini} (ed.) et al., Large truncated Toeplitz matrices, Toeplitz operators, and related topics. The Albrecht Böttcher anniversary volume. Basel: Birkhäuser/Springer (2017; Zbl 1367.47005) Full Text: DOI
Spitkovsky, Ilya M.; Weis, Stephan Pre-images of extreme points of the numerical range, and applications. (English) Zbl 1355.15016 Oper. Matrices 10, No. 4, 1043-1058 (2016). MSC: 15A60 PDFBibTeX XMLCite \textit{I. M. Spitkovsky} and \textit{S. Weis}, Oper. Matrices 10, No. 4, 1043--1058 (2016; Zbl 1355.15016) Full Text: DOI arXiv
Johnson, Charles R.; Spitkovsky, Ilya M.; Stevanovic, Mirjana; Turnansky, Morrison Normal matrices subordinate to a tree and flat portions of the field of values. (English) Zbl 1343.05093 Linear Algebra Appl. 507, 198-207 (2016). MSC: 05C50 05B20 05C05 15A60 15B57 PDFBibTeX XMLCite \textit{C. R. Johnson} et al., Linear Algebra Appl. 507, 198--207 (2016; Zbl 1343.05093) Full Text: DOI
Leake, Timothy; Lins, Brian; Spitkovsky, Ilya M. Corrections and additions to: “Inverse continuity on the boundary of the numerical range”. (English) Zbl 1383.15021 Linear Multilinear Algebra 64, No. 1, 100-104 (2016). MSC: 15A60 15A63 15A18 PDFBibTeX XMLCite \textit{T. Leake} et al., Linear Multilinear Algebra 64, No. 1, 100--104 (2016; Zbl 1383.15021) Full Text: DOI
Ephremidze, Lasha; Spitkovsky, Ilya Matrix spectral factorization with perturbed data. (English) Zbl 1336.15006 Mem. Differ. Equ. Math. Phys. 66, 65-82 (2015). MSC: 15A23 15A54 65F30 15A60 PDFBibTeX XMLCite \textit{L. Ephremidze} and \textit{I. Spitkovsky}, Mem. Differ. Equ. Math. Phys. 66, 65--82 (2015; Zbl 1336.15006) Full Text: Link
Spitkovsky, Ilya M.; Thomas, Claire Marie Line segments on the boundary of the numerical ranges of some tridiagonal matrices. (English) Zbl 1328.15037 Electron. J. Linear Algebra 30, 693-703 (2015). MSC: 15A60 PDFBibTeX XMLCite \textit{I. M. Spitkovsky} and \textit{C. M. Thomas}, Electron. J. Linear Algebra 30, 693--703 (2015; Zbl 1328.15037) Full Text: DOI Link
Chien, Ruey Ting; Spitkovsky, Ilya M. On the numerical ranges of some tridiagonal matrices. (English) Zbl 1309.15036 Linear Algebra Appl. 470, 228-240 (2015). MSC: 15A60 PDFBibTeX XMLCite \textit{R. T. Chien} and \textit{I. M. Spitkovsky}, Linear Algebra Appl. 470, 228--240 (2015; Zbl 1309.15036) Full Text: DOI
Rodman, Leiba; Spitkovsky, Ilya M. Factorization of matrices with symmetries over function algebras. (English) Zbl 1311.15015 Integral Equations Oper. Theory 80, No. 4, 469-510 (2014). Reviewer: Erich W. Ellers (Toronto) MSC: 15A23 15A54 PDFBibTeX XMLCite \textit{L. Rodman} and \textit{I. M. Spitkovsky}, Integral Equations Oper. Theory 80, No. 4, 469--510 (2014; Zbl 1311.15015) Full Text: DOI
Leake, Timothy; Lins, Brian; Spitkovsky, Ilya M. Pre-images of boundary points of the numerical range. (English) Zbl 1309.15038 Oper. Matrices 8, No. 3, 699-724 (2014). Reviewer: Rabe von Randow (Bonn) MSC: 15A60 47A12 54C08 PDFBibTeX XMLCite \textit{T. Leake} et al., Oper. Matrices 8, No. 3, 699--724 (2014; Zbl 1309.15038) Full Text: DOI Link
Leake, Timothy; Lins, Brian; Spitkovsky, Ilya M. Inverse continuity on the boundary of the numerical range. (English) Zbl 1312.15028 Linear Multilinear Algebra 62, No. 10, 1335-1345 (2014); corrections and additions ibid. 64, No. 1, 100-104 (2016). Reviewer: Matthew C. Lettington (Cardiff) MSC: 15A60 15A63 15A18 PDFBibTeX XMLCite \textit{T. Leake} et al., Linear Multilinear Algebra 62, No. 10, 1335--1345 (2014; Zbl 1312.15028) Full Text: DOI arXiv
Camenga, Kristin A.; Rault, Patrick X.; Sendova, Tsvetanka; Spitkovsky, Ilya M. On the Gau-Wu number for some classes of matrices. (English) Zbl 1292.15020 Linear Algebra Appl. 444, 254-262 (2014). MSC: 15A60 PDFBibTeX XMLCite \textit{K. A. Camenga} et al., Linear Algebra Appl. 444, 254--262 (2014; Zbl 1292.15020) Full Text: DOI
Camenga, Kristin A.; Rault, Patrick X.; Rossi, Daniel J.; Sendova, Tsvetanka; Spitkovsky, Ilya M. Numerical range of some doubly stochastic matrices. (English) Zbl 1329.15068 Appl. Math. Comput. 221, 40-47 (2013). Reviewer: Pham Viet Hai (Hanoi) MSC: 15B51 15A60 PDFBibTeX XMLCite \textit{K. A. Camenga} et al., Appl. Math. Comput. 221, 40--47 (2013; Zbl 1329.15068) Full Text: DOI
Moran, Tyler; Spitkovsky, Ilya On almost normal matrices. (English) Zbl 1391.15112 Fonseca, Carlos (ed.) et al., The Natália Bebiano anniversary volume. Special issue on the occasion of her 60th birthday. Coimbra: Universidade de Coimbra, Departamento de Matemática (ISBN 978-972-8564-48-3/pbk). Textos de Matemática 44, 131-144 (2013). Reviewer: Jorma K. Merikoski (Tampere) MSC: 15B57 15A60 15A27 PDFBibTeX XMLCite \textit{T. Moran} and \textit{I. Spitkovsky}, Textos Mat. 44, 131--144 (2013; Zbl 1391.15112)
Rodman, Leiba; Spitkovsky, Ilya M. On numerical ranges of rank-two operators. (English) Zbl 1303.47009 Integral Equations Oper. Theory 77, No. 3, 441-448 (2013). Reviewer: Jorma K. Merikoski (Tampere) MSC: 47A12 15A60 47B99 PDFBibTeX XMLCite \textit{L. Rodman} and \textit{I. M. Spitkovsky}, Integral Equations Oper. Theory 77, No. 3, 441--448 (2013; Zbl 1303.47009) Full Text: DOI
Johnson, Charles R.; Price, Zachary; Spitkovsky, Ilya M. The distribution of eigenvalues of doubly cyclic \(Z^+\)-matrices. (English) Zbl 1283.15059 Linear Algebra Appl. 439, No. 11, 3576-3580 (2013). MSC: 15A42 15B05 15A15 PDFBibTeX XMLCite \textit{C. R. Johnson} et al., Linear Algebra Appl. 439, No. 11, 3576--3580 (2013; Zbl 1283.15059) Full Text: DOI
Rault, Patrick X.; Sendova, Tsvetanka; Spitkovsky, Ilya M. 3-by-3 matrices with elliptical numerical range revisited. (English) Zbl 1283.15072 Electron. J. Linear Algebra 26, 158-167 (2013). MSC: 15A60 15A18 PDFBibTeX XMLCite \textit{P. X. Rault} et al., Electron. J. Linear Algebra 26, 158--167 (2013; Zbl 1283.15072) Full Text: DOI Link
Corey, Dan; Johnson, Charles R.; Kirk, Ryan; Lins, Brian; Spitkovsky, Ilya Continuity properties of vectors realizing points in the classical field of values. (English) Zbl 1290.15012 Linear Multilinear Algebra 61, No. 10, 1329-1338 (2013). Reviewer: Wai-Shun Cheung (Hong Kong) MSC: 15A60 47A12 54C08 54C60 PDFBibTeX XMLCite \textit{D. Corey} et al., Linear Multilinear Algebra 61, No. 10, 1329--1338 (2013; Zbl 1290.15012) Full Text: DOI arXiv
Corey, Daniel; Johnson, Charles R.; Kirk, Ryan; Lins, Brian; Spitkovsky, Ilya The product field of values. (English) Zbl 1272.15015 Linear Algebra Appl. 438, No. 5, 2155-2173 (2013). Reviewer: Wai-Shun Cheung (Hong Kong) MSC: 15A60 15B57 PDFBibTeX XMLCite \textit{D. Corey} et al., Linear Algebra Appl. 438, No. 5, 2155--2173 (2013; Zbl 1272.15015) Full Text: DOI
Böttcher, A.; Spitkovsky, I. M. Group inversion in certain finite-dimensional algebras generated by two idempotents. (English) Zbl 1262.15018 Indag. Math., New Ser. 23, No. 4, 715-732 (2012). Reviewer: Mart Abel (Tartu) MSC: 15A30 15A09 16S15 46H15 47L15 16P10 PDFBibTeX XMLCite \textit{A. Böttcher} and \textit{I. M. Spitkovsky}, Indag. Math., New Ser. 23, No. 4, 715--732 (2012; Zbl 1262.15018) Full Text: DOI
Eldred, Jeffrey; Rodman, Leiba; Spitkovsky, Ilya Numerical ranges of companion matrices: flat portions on the boundary. (English) Zbl 1262.15025 Linear Multilinear Algebra 60, No. 11-12, 1295-1311 (2012). Reviewer: Pei Yuan Wu (Hsinchu) MSC: 15A60 PDFBibTeX XMLCite \textit{J. Eldred} et al., Linear Multilinear Algebra 60, No. 11--12, 1295--1311 (2012; Zbl 1262.15025) Full Text: DOI arXiv
Helton, J. William; Spitkovsky, I. M. The possible shapes of numerical ranges. (English) Zbl 1270.15014 Oper. Matrices 6, No. 3, 607-611 (2012). Reviewer: João R. Cardoso (Coimbra) MSC: 15A60 15A45 15B57 PDFBibTeX XMLCite \textit{J. W. Helton} and \textit{I. M. Spitkovsky}, Oper. Matrices 6, No. 3, 607--611 (2012; Zbl 1270.15014) Full Text: DOI arXiv Link
Harris, Thomas Ryan; Mazzella, Michael; Patton, Linda J.; Renfrew, David; Spitkovsky, Ilya M. Numerical ranges of cube roots of the identity. (English) Zbl 1221.47012 Linear Algebra Appl. 435, No. 11, 2639-2657 (2011). MSC: 47A12 15A60 PDFBibTeX XMLCite \textit{T. R. Harris} et al., Linear Algebra Appl. 435, No. 11, 2639--2657 (2011; Zbl 1221.47012) Full Text: DOI
Böttcher, A.; Spitkovsky, I. M. On certain finite-dimensional algebras generated by two idempotents. (English) Zbl 1235.15017 Linear Algebra Appl. 435, No. 8, 1823-1836 (2011). Reviewer: Marjeta Kramar Fijavž (Ljubljana) MSC: 15A30 15A09 16R50 46H15 47L55 PDFBibTeX XMLCite \textit{A. Böttcher} and \textit{I. M. Spitkovsky}, Linear Algebra Appl. 435, No. 8, 1823--1836 (2011; Zbl 1235.15017) Full Text: DOI
Bastos, M. A.; Bravo, A.; Karlovich, Yu. I.; Spitkovsky, I. M. Constructive factorization of some almost periodic triangular matrix functions with a quadrinomial off diagonal entry. (English) Zbl 1211.15018 J. Math. Anal. Appl. 376, No. 2, 625-640 (2011). Reviewer: Erich W. Ellers (Toronto) MSC: 15A23 47A68 42A75 PDFBibTeX XMLCite \textit{M. A. Bastos} et al., J. Math. Anal. Appl. 376, No. 2, 625--640 (2011; Zbl 1211.15018) Full Text: DOI
Einstein, Eduard; Johnson, Charles R.; Lins, Brian; Spitkovsky, Ilya The ratio field of values. (English) Zbl 1209.15024 Linear Algebra Appl. 434, No. 4, 1119-1136 (2011). Reviewer: Alexey Alimov (Moskva) MSC: 15A60 15A18 15A22 15A54 PDFBibTeX XMLCite \textit{E. Einstein} et al., Linear Algebra Appl. 434, No. 4, 1119--1136 (2011; Zbl 1209.15024) Full Text: DOI
Câmara, M. C.; Karlovich, Yu. I.; Spitkovsky, I. M. Constructive almost periodic factorization of some triangular matrix functions. (English) Zbl 1206.42006 J. Math. Anal. Appl. 367, No. 2, 416-433 (2010). Reviewer: Angela Albanese (Lecce) MSC: 42A75 15A23 PDFBibTeX XMLCite \textit{M. C. Câmara} et al., J. Math. Anal. Appl. 367, No. 2, 416--433 (2010; Zbl 1206.42006) Full Text: DOI
Rodman, Leiba; Seyalioglu, Hakan; Spitkovsky, Ilya M. On common invariant cones for families of matrices. (English) Zbl 1188.15028 Linear Algebra Appl. 432, No. 4, 911-926 (2010). Reviewer: Juan Ramon Torregrosa Sanchez (Valencia) MSC: 15B48 15A18 15A21 PDFBibTeX XMLCite \textit{L. Rodman} et al., Linear Algebra Appl. 432, No. 4, 911--926 (2010; Zbl 1188.15028) Full Text: DOI arXiv Link
Böttcher, A.; Spitkovsky, I. M. A gentle guide to the basics of two projections theory. (English) Zbl 1189.47073 Linear Algebra Appl. 432, No. 6, 1412-1459 (2010). Reviewer: Mohammad Sal Moslehian (Mashhad) MSC: 47L15 15A21 15A30 47C15 46L89 46H15 16S50 47-02 PDFBibTeX XMLCite \textit{A. Böttcher} and \textit{I. M. Spitkovsky}, Linear Algebra Appl. 432, No. 6, 1412--1459 (2010; Zbl 1189.47073) Full Text: DOI Link
Gohberg, Israel; Krupnik, Nahum; Heinig, Georg Lerer, Leonid (ed.); Olshevsky, Vadim (ed.); Spitkovsky, Ilya M. (ed.) Convolution equations and singular integral operators. Selected papers of Israel Gohberg and Georg Heinig, Israel Gohberg and Nahum Krupnik. Transl. from the Russian by Oleksiy Karlovych. Edited by Leonid Lerer, Vadim Olshevsky and Ilya M. Spitkovsky. (English) Zbl 1218.00015 Operator Theory: Advances and Applications 206. Basel: Birkhäuser (ISBN 978-3-7643-8955-0/hbk). xxii, 217 p. (2010). Reviewer: Albrecht Böttcher (Chemnitz) MSC: 00B50 15-06 47-06 PDFBibTeX XMLCite \textit{I. Gohberg} et al., Convolution equations and singular integral operators. Selected papers of Israel Gohberg and Georg Heinig, Israel Gohberg and Nahum Krupnik. Transl. from the Russian by Oleksiy Karlovych. Edited by Leonid Lerer, Vadim Olshevsky and Ilya M. Spitkovsky. Basel: Birkhäuser (2010; Zbl 1218.00015) Full Text: DOI
Kaliuzhnyi-Verbovetskyi, Dmitry S.; Spitkovsky, Ilya M.; Woerdeman, Hugo J. Matrices with normal defect one. (English) Zbl 1181.15045 Oper. Matrices 3, No. 3, Article ID 24, 401-438 (2009). Reviewer: Grozio Stanilov (Sofia) MSC: 15B57 47A20 47B15 81P68 15A83 15A60 PDFBibTeX XMLCite \textit{D. S. Kaliuzhnyi-Verbovetskyi} et al., Oper. Matrices 3, No. 3, Article ID 24, 401--438 (2009; Zbl 1181.15045) Full Text: arXiv Link
Rose, David E. V.; Spitkovsky, Ilya M. On the stabilization of the Aluthge sequence. (English) Zbl 1164.15005 Int. J. Inf. Syst. Sci. 4, No. 1, 178-189 (2008). MSC: 15A60 15A99 PDFBibTeX XMLCite \textit{D. E. V. Rose} and \textit{I. M. Spitkovsky}, Int. J. Inf. Syst. Sci. 4, No. 1, 178--189 (2008; Zbl 1164.15005)
Hoai, Bich T.; Johnson, Charles R.; Spitkovsky, Ilya M. Spectral dominance and commuting chains. (English) Zbl 1147.47010 Proc. Am. Math. Soc. 136, No. 6, 2019-2029 (2008). Reviewer: Hu Yong-Jian (Beijing) MSC: 47A46 47B65 15B57 PDFBibTeX XMLCite \textit{B. T. Hoai} et al., Proc. Am. Math. Soc. 136, No. 6, 2019--2029 (2008; Zbl 1147.47010) Full Text: DOI
Rose, David E. V.; Spitkovsky, Ilya M. On the numerical range behavior under the generalized Aluthge transform. (English) Zbl 1137.15017 Linear Multilinear Algebra 56, No. 1-2, 163-177 (2008). Reviewer: Mohammad Sal Moslehian (Mashhad) MSC: 15A60 15A23 PDFBibTeX XMLCite \textit{D. E. V. Rose} and \textit{I. M. Spitkovsky}, Linear Multilinear Algebra 56, No. 1--2, 163--177 (2008; Zbl 1137.15017) Full Text: DOI
Krupnik, Naum; Spitkovsky, Ilya M. Sets of matrices with given joint numerical range. (English) Zbl 1110.15026 Linear Algebra Appl. 419, No. 2-3, 569-585 (2006). Reviewer: Alexey Alimov (Moskva) MSC: 15A60 15A21 PDFBibTeX XMLCite \textit{N. Krupnik} and \textit{I. M. Spitkovsky}, Linear Algebra Appl. 419, No. 2--3, 569--585 (2006; Zbl 1110.15026) Full Text: DOI
Spitkovsky, Ilya M. On polynomials in two projections. (English) Zbl 1092.15011 Electron. J. Linear Algebra 15, 154-158 (2006). Reviewer: Vladimir P. Kostov (Nice) MSC: 15A24 15A27 PDFBibTeX XMLCite \textit{I. M. Spitkovsky}, Electron. J. Linear Algebra 15, 154--158 (2006; Zbl 1092.15011) Full Text: DOI EuDML Link Link
Rodman, Leiba; Spitkovsky, Ilya M. Analytic roots of invertible matrix functions. (English) Zbl 1117.47011 Electron. J. Linear Algebra 13, 187-196 (2005). Reviewer: Birgit Jacob (Delft) MSC: 47A56 15A99 30G30 39B42 47A68 PDFBibTeX XMLCite \textit{L. Rodman} and \textit{I. M. Spitkovsky}, Electron. J. Linear Algebra 13, 187--196 (2005; Zbl 1117.47011) Full Text: DOI EuDML EMIS
Bini, Dario A.; Meini, Beatrice; Spitkovsky, Ilya M. Shift techniques and canonical factorizations in the solution of M/G/1-type Markov chains. (English) Zbl 1075.60091 Stoch. Models 21, No. 2-3, 279-302 (2005). Reviewer: Alex V. Kolnogorov (Novgorod) MSC: 60J22 15A24 47B35 60K25 PDFBibTeX XMLCite \textit{D. A. Bini} et al., Stoch. Models 21, No. 2--3, 279--302 (2005; Zbl 1075.60091) Full Text: DOI
Rodman, L.; Spitkovsky, I. M. 3 x 3 matrices with a flat portion on the boundary of the numerical range. (English) Zbl 1071.15029 Linear Algebra Appl. 397, 193-207 (2005). Reviewer: Salah Mecheri (Riyadh) MSC: 15A60 PDFBibTeX XMLCite \textit{L. Rodman} and \textit{I. M. Spitkovsky}, Linear Algebra Appl. 397, 193--207 (2005; Zbl 1071.15029) Full Text: DOI
Brown, Ethan S.; Spitkovsky, Ilya M. On flat portions on the boundary of the numerical range. (English) Zbl 1059.15031 Linear Algebra Appl. 390, 75-109 (2004). Reviewer: Alexey Alimov (Moskva) MSC: 15A60 PDFBibTeX XMLCite \textit{E. S. Brown} and \textit{I. M. Spitkovsky}, Linear Algebra Appl. 390, 75--109 (2004; Zbl 1059.15031) Full Text: DOI
Brown, Ethan S.; Spitkovsky, Ilya M. On matrices with elliptical numerical ranges. (English) Zbl 1059.15030 Linear Multilinear Algebra 52, No. 3-4, 177-193 (2004). Reviewer: Pei Yuan Wu (Hsinchu) MSC: 15A60 47A12 47B36 PDFBibTeX XMLCite \textit{E. S. Brown} and \textit{I. M. Spitkovsky}, Linear Multilinear Algebra 52, No. 3--4, 177--193 (2004; Zbl 1059.15030) Full Text: DOI
Li, Chi-Kwong; Spitkovsky, Ilya; Zobin, Nahum Finite reflection groups and linear preserver problems. (English) Zbl 1060.15007 Rocky Mt. J. Math. 34, No. 1, 225-251 (2004). Reviewer: Erich W. Ellers (Toronto) MSC: 15A04 20F55 PDFBibTeX XMLCite \textit{C.-K. Li} et al., Rocky Mt. J. Math. 34, No. 1, 225--251 (2004; Zbl 1060.15007) Full Text: DOI
Rodman, Leiba; Spitkovsky, Ilya M.; Woerdeman, Hugo J. Noncanonical factorizations of almost periodic multivariable matrix functions. (English) Zbl 1079.47019 Böttcher, Albrecht (ed.) et al., Singular integral operators, factorization and applications. Proceedings of the 12th international workshop on operator theory and applications, IWOTA 2000, Faro, Portugal, September 12–15, 2000. Basel: Birkhäuser (ISBN 3-7643-6947-7/hbk). Oper. Theory, Adv. Appl. 142, 311-344 (2003). Reviewer: Maria Amelia Bastos (Lisboa) MSC: 47A56 42A75 26B99 15A54 47A68 47B35 PDFBibTeX XMLCite \textit{L. Rodman} et al., in: Singular integral operators, factorization and applications. Proceedings of the 12th international workshop on operator theory and applications, IWOTA 2000, Faro, Portugal, September 12--15, 2000. Basel: Birkhäuser. 311--344 (2003; Zbl 1079.47019)
Rodman, Leiba; Spitkovsky, Ilya M.; Woerdeman, Hugo J. Contractive extension problems for matrix valued almost periodic functions of several variables. (English) Zbl 1025.42011 J. Oper. Theory 47, No. 1, 3-35 (2002). Reviewer: A.Gheondea (Bucureşti) MSC: 42B99 42A75 47A56 42A82 47B35 15A54 PDFBibTeX XMLCite \textit{L. Rodman} et al., J. Oper. Theory 47, No. 1, 3--35 (2002; Zbl 1025.42011)
Rodman, Leiba; Spitkovsky, Ilya M.; Woerdeman, Hugo J. Abstract band method via factorization, positive and band extensions of multivariable almost periodic matrix functions, and spectral estimation. (English) Zbl 1017.47014 Mem. Am. Math. Soc. 762, 71 p. (2002). Reviewer: F.H.Vasilescu (Villeneuve d’Ascq) MSC: 47A57 42A75 47A68 15A54 47B35 42A82 93E10 60G12 PDFBibTeX XMLCite \textit{L. Rodman} et al., Abstract band method via factorization, positive and band extensions of multivariable almost periodic matrix functions, and spectral estimation. Providence, RI: American Mathematical Society (AMS) (2002; Zbl 1017.47014) Full Text: DOI
Hillar, C.; Johnson, C. R.; Spitkovsky, I. M. Positive eigenvalues and two-letter generalized words. (English) Zbl 0997.15009 Electron. J. Linear Algebra 9, 21-26 (2002). Reviewer: Václav Burjan (Praha) MSC: 15A18 03D40 06B25 08A50 15B57 20F10 68R15 PDFBibTeX XMLCite \textit{C. Hillar} et al., Electron. J. Linear Algebra 9, 21--26 (2002; Zbl 0997.15009) Full Text: DOI arXiv EuDML EMIS
Okubo, Kazuyoshi; Spitkovsky, Ilya On the characterization of \(2\times 2\) \(\rho\)-contraction matrices. (English) Zbl 0989.15010 Linear Algebra Appl. 325, No. 1-3, 177-189 (2001). Reviewer: Valeriu Prepeliţă (Bucureşti) MSC: 15A60 47A12 47A20 PDFBibTeX XMLCite \textit{K. Okubo} and \textit{I. Spitkovsky}, Linear Algebra Appl. 325, No. 1--3, 177--189 (2001; Zbl 0989.15010) Full Text: DOI
Caston, Lauren; Savova, Milena; Spitkovsky, Ilya; Zobin, Nahum On eigenvalues and boundary curvature of the numerical range. (English) Zbl 0969.15014 Linear Algebra Appl. 322, No. 1-3, 129-140 (2001). Reviewer: Alexey Alimov (Moskva) MSC: 15A60 15A42 PDFBibTeX XMLCite \textit{L. Caston} et al., Linear Algebra Appl. 322, No. 1--3, 129--140 (2001; Zbl 0969.15014) Full Text: DOI
Spitkovsky, Ilya M.; Yong, Darryl Almost periodic factorization of certain block triangular matrix functions. (English) Zbl 0955.47016 Math. Comput. 69, No. 231, 1053-1070 (2000). Reviewer: A.Sołtysiak (Poznań) MSC: 47A68 47-04 42A75 65F05 15A23 PDFBibTeX XMLCite \textit{I. M. Spitkovsky} and \textit{D. Yong}, Math. Comput. 69, No. 231, 1053--1070 (2000; Zbl 0955.47016) Full Text: DOI
Karlovich, Yuri I.; Spitkovsky, Ilya M.; Walker, Ronald A. Almost periodic factorization of block triangular matrix functions revisited. (English) Zbl 0951.42005 Linear Algebra Appl. 293, No. 1-3, 199-232 (1999). Reviewer: Erich Ellers (Toronto) MSC: 42A75 15A23 47A68 PDFBibTeX XMLCite \textit{Y. I. Karlovich} et al., Linear Algebra Appl. 293, No. 1--3, 199--232 (1999; Zbl 0951.42005) Full Text: DOI
Bakonyi, M.; Rodman, L.; Spitkovsky, I. M.; Woerdeman, H. J. Positive matrix functions on the bitorus with prescribed Fourier coefficients in a band. (English) Zbl 0930.42010 J. Fourier Anal. Appl. 5, No. 1, 21-44 (1999). Reviewer: I.Valuşescu (Bucureşti) MSC: 42B99 47B35 15A54 60G35 PDFBibTeX XMLCite \textit{M. Bakonyi} et al., J. Fourier Anal. Appl. 5, No. 1, 21--44 (1999; Zbl 0930.42010) Full Text: DOI EuDML
Keeler, Dennis S.; Rodman, Leiba; Spitkovsky, Ilya M. The numerical range of \(3 \times 3\) matrices. (English) Zbl 0876.15020 Linear Algebra Appl. 252, 115-139 (1997). Reviewer: R.von Randow (Bonn) MSC: 15A60 PDFBibTeX XMLCite \textit{D. S. Keeler} et al., Linear Algebra Appl. 252, 115--139 (1997; Zbl 0876.15020) Full Text: DOI
Johnson, Charles R.; Spitkovsky, I. M.; Gottlieb, S. Inequalities involving the numerical radius. (English) Zbl 0814.15017 Linear Multilinear Algebra 37, No. 1-3, 13-24 (1994). Reviewer: J.Szilasi (Debrecen) MSC: 15A60 15A45 PDFBibTeX XMLCite \textit{C. R. Johnson} et al., Linear Multilinear Algebra 37, No. 1--3, 13--24 (1994; Zbl 0814.15017) Full Text: DOI
Johnson, Charles R.; Li, Chi-Kwong; Rodman, Leiba; Spitkovsky, Ilya; Pierce, Stephen Linear maps preserving regional eigenvalue location. (English) Zbl 0761.15018 Linear Multilinear Algebra 32, No. 3-4, 253-264 (1992). Reviewer: J.D.Dixon (Ottawa) MSC: 15A42 15A22 15A30 PDFBibTeX XMLCite \textit{C. R. Johnson} et al., Linear Multilinear Algebra 32, No. 3--4, 253--264 (1992; Zbl 0761.15018) Full Text: DOI
Spitkovskij, I. M.; Tashbaev, A. M. Factorization of piecewise constant matrix-valued functions with 3 points of discontinuity in \(L_{p,p}\) classes and some of its applications. (English. Russian original) Zbl 0696.15012 Sov. Math., Dokl. 40, No. 1, 80-85 (1990); translation from Dokl. Akad. Nauk SSSR 307, No. 1-6, 291-296 (1989). Reviewer: G.P.Barker MSC: 15A23 15A60 30E25 PDFBibTeX XMLCite \textit{I. M. Spitkovskij} and \textit{A. M. Tashbaev}, Sov. Math., Dokl. 40, No. 1, 80--85 (1990; Zbl 0696.15012); translation from Dokl. Akad. Nauk SSSR 307, No. 1--6, 291--296 (1989)
Spitkovskij, I. M.; Tishin, P. M. Partial indices of triangular matrices of order higher than 2. (English. Russian original) Zbl 0661.15010 Ukr. Math. J. 39, No. 6, 611-615 (1987); translation from Ukr. Mat. Zh. 39, No. 6, 751-756 (1987). MSC: 15A23 15A54 46E40 PDFBibTeX XMLCite \textit{I. M. Spitkovskij} and \textit{P. M. Tishin}, Ukr. Math. J. 39, No. 6, 611--615 (1987; Zbl 0661.15010); translation from Ukr. Mat. Zh. 39, No. 6, 751--756 (1987) Full Text: DOI
Spitkovskij, I. M.; Tishin, P. M. On partial indices of triangular matrices of order \(>2\). (Russian) Zbl 0651.15010 Ukr. Mat. Zh. 39, No. 6, 751-756 (1987). Reviewer: K.Heuvers MSC: 15A23 15A54 46E40 PDFBibTeX XMLCite \textit{I. M. Spitkovskij} and \textit{P. M. Tishin}, Ukr. Mat. Zh. 39, No. 6, 751--756 (1987; Zbl 0651.15010)
Krejn, M. G.; Spitkovskij, I. M. Some generalizations of Szegö’s first limit theorem. (Russian. English summary) Zbl 0582.15008 Anal. Math. 9, No. 1, 23-41 (1983). MSC: 15B57 PDFBibTeX XMLCite \textit{M. G. Krejn} and \textit{I. M. Spitkovskij}, Anal. Math. 9, 23--41 (1983; Zbl 0582.15008) Full Text: DOI
Krejn, M. G.; Spitkovskij, I. M. Über die Faktorisierung alpha-sektorialer Matrixfunktionen auf der Einheitsperipherie. (Russian) Zbl 0499.47015 Mat. Issled. 47, 41-63 (1978). MSC: 47A68 46J15 15A23 15A60 PDFBibTeX XMLCite \textit{M. G. Krejn} and \textit{I. M. Spitkovskij}, Mat. Issled. 47, 41--63 (1978; Zbl 0499.47015)
Spitkovskii, I. M. Über die Wiederherstellung eines unitären Operators aus seinen zwei diagonalen Blöcken. (Russian) Zbl 0313.47015 Mat. Issled. 8, No. 4(30), 187-193 (1973). MSC: 47B15 47B35 15A24 PDFBibTeX XMLCite \textit{I. M. Spitkovskii}, Mat. Issled. 8, No. 4(30), 187--193 (1973; Zbl 0313.47015)