Kirkland, Stephen; Laffey, Thomas; Šmigoc, Helena The Karpelevič region revisited. (English) Zbl 1445.15022 J. Math. Anal. Appl. 490, No. 2, Article ID 124332, 16 p. (2020). MSC: 15B51 15A18 PDFBibTeX XMLCite \textit{S. Kirkland} et al., J. Math. Anal. Appl. 490, No. 2, Article ID 124332, 16 p. (2020; Zbl 1445.15022) Full Text: DOI arXiv
Kokol Bukovšek, Damjana; Laffey, Thomas; Šmigoc, Helena Completely positive factorizations associated with Euclidean distance matrices corresponding to an arithmetic progression. (English) Zbl 1437.15045 Linear Algebra Appl. 597, 113-132 (2020). Reviewer: Erich W. Ellers (Toronto) MSC: 15B48 15A23 15B36 PDFBibTeX XMLCite \textit{D. Kokol Bukovšek} et al., Linear Algebra Appl. 597, 113--132 (2020; Zbl 1437.15045) Full Text: DOI arXiv
Laffey, Thomas; Šmigoc, Helena The integer cp-rank of \(2 \times 2\) matrices. (English) Zbl 1433.15033 Spec. Matrices 7, 272-275 (2019). MSC: 15B36 15B48 PDFBibTeX XMLCite \textit{T. Laffey} and \textit{H. Šmigoc}, Spec. Matrices 7, 272--275 (2019; Zbl 1433.15033) Full Text: DOI arXiv
Laffey, Thomas J.; Šmigoc, Helena Integer completely positive matrices of order two. (English) Zbl 1474.15082 Pure Appl. Funct. Anal. 3, No. 4, 633-638 (2018). MSC: 15B36 15A23 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Pure Appl. Funct. Anal. 3, No. 4, 633--638 (2018; Zbl 1474.15082) Full Text: arXiv Link
Laffey, Thomas J.; Šmigoc, Helena Diagonal realizability in the nonnegative inverse eigenvalue problem. (English) Zbl 1474.15046 Pure Appl. Funct. Anal. 3, No. 4, 625-631 (2018). MSC: 15A29 15A20 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Pure Appl. Funct. Anal. 3, No. 4, 625--631 (2018; Zbl 1474.15046) Full Text: arXiv Link
Guterman, Alexander; Laffey, Thomas; Markova, Olga; Šmigoc, Helena A resolution of Paz’s conjecture in the presence of a nonderogatory matrix. (English) Zbl 1382.15027 Linear Algebra Appl. 543, 234-250 (2018). MSC: 15A30 13E10 16S50 15A21 PDFBibTeX XMLCite \textit{A. Guterman} et al., Linear Algebra Appl. 543, 234--250 (2018; Zbl 1382.15027) Full Text: DOI
Laffey, Thomas; Markova, Olga; Šmigoc, Helena The effect of assuming the identity as a generator on the length of the matrix algebra. (English) Zbl 1334.15051 Linear Algebra Appl. 498, 378-393 (2016). MSC: 15A30 13E10 16S50 PDFBibTeX XMLCite \textit{T. Laffey} et al., Linear Algebra Appl. 498, 378--393 (2016; Zbl 1334.15051) Full Text: DOI arXiv
Laffey, Thomas J.; Loewy, Raphael; Šmigoc, Helena Power series with positive coefficients arising from the characteristic polynomials of positive matrices. (English) Zbl 1345.15011 Math. Ann. 364, No. 1-2, 687-707 (2016). Reviewer: Alexander Kovačec (Coimbra); Frank Uhlig (Auburn) MSC: 15B48 15A29 15A18 30B10 37B10 PDFBibTeX XMLCite \textit{T. J. Laffey} et al., Math. Ann. 364, No. 1--2, 687--707 (2016; Zbl 1345.15011) Full Text: DOI arXiv
Cronin, Anthony G.; Laffey, Thomas J. On a conjecture of Deveci and Karaduman. (English) Zbl 1310.15058 Linear Algebra Appl. 471, 569-574 (2015). MSC: 15B36 20F05 20D60 11A41 15A23 PDFBibTeX XMLCite \textit{A. G. Cronin} and \textit{T. J. Laffey}, Linear Algebra Appl. 471, 569--574 (2015; Zbl 1310.15058) Full Text: DOI
Cronin, Anthony G.; Laffey, Thomas J. Perturbations on constructible lists preserving realizability in the NIEP and questions of Monov. (English) Zbl 1321.15032 Linear Algebra Appl. 445, 206-222 (2014). MSC: 15A29 15A18 PDFBibTeX XMLCite \textit{A. G. Cronin} and \textit{T. J. Laffey}, Linear Algebra Appl. 445, 206--222 (2014; Zbl 1321.15032) Full Text: DOI
Gow, Rod; Laffey, Thomas J. A Pascal type matrix and the tensor product of Jordan blocks. (English) Zbl 1301.15011 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, 53-57 (2013). Reviewer: A. Arvanitoyeorgos (Patras) MSC: 15A21 15A23 20C20 15B36 15A69 PDFBibTeX XMLCite \textit{R. Gow} and \textit{T. J. Laffey}, Textos Mat. 44, 53--57 (2013; Zbl 1301.15011)
Laffey, Thomas J. Formal power series and the spectra of nonnegative real matrices. (English) Zbl 1296.15006 Math. Proc. R. Ir. Acad. 113A, No. 2, 97-106 (2013). Reviewer: Mihail Voicu (Iaşi) MSC: 15A18 15A29 15A42 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey}, Math. Proc. R. Ir. Acad. 113A, No. 2, 97--106 (2013; Zbl 1296.15006) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena Simultaneous reduction of matrices in the presence of a nonderogatory matrix. (English) Zbl 1281.15010 Linear Algebra Appl. 438, No. 10, 3885-3890 (2013). MSC: 15A21 15A27 47A15 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Algebra Appl. 438, No. 10, 3885--3890 (2013; Zbl 1281.15010) Full Text: DOI
Cronin, Anthony G.; Laffey, Thomas J. An inequality for the spectra of nonnegative matrices. (English) Zbl 1239.15013 Linear Algebra Appl. 436, No. 9, 3225-3238 (2012). MSC: 15A42 15A18 15A29 PDFBibTeX XMLCite \textit{A. G. Cronin} and \textit{T. J. Laffey}, Linear Algebra Appl. 436, No. 9, 3225--3238 (2012; Zbl 1239.15013) Full Text: DOI
Laffey, Thomas J. A constructive version of the Boyle-Handelman theorem on the spectra of nonnegative matrices. (English) Zbl 1241.15007 Linear Algebra Appl. 436, No. 6, 1701-1709 (2012). Reviewer: Süleyman Güler (Aydin) MSC: 15A18 15A29 15A42 15B36 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 436, No. 6, 1701--1709 (2012; Zbl 1241.15007) Full Text: DOI arXiv
Laffey, Thomas J.; Šmigoc, Helena Nonnegatively realizable spectra with two positive eigenvalues. (English) Zbl 1205.15019 Linear Multilinear Algebra 58, No. 7-8, 1053-1069 (2010). Reviewer: Valeriu Prepeliţă (Bucureşti) MSC: 15A18 15A29 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Multilinear Algebra 58, No. 7--8, 1053--1069 (2010; Zbl 1205.15019) Full Text: DOI
Semigroups Working Group at LAW’08 [Radjavi, Hejdar; Drnovšek, Roman; Bernik, Janez; Cigler, Grega; Jafarian, Ali A.; Bukovšek, Damjana Kokol; Košir, Tomaž; Fijavž, Marjeta Kramar; Kudryavtseva, Ganna; Laffey, Thomas; Livshits, Leo; MacDonald; Gordon W. Omladič, Matjaž; Rosenthal, Peter] Semigroups of operators with nonnegative diagonals. (English) Zbl 1202.47049 Linear Algebra Appl. 433, No. 11-12, 2080-2087 (2010). MSC: 47D03 15B48 47A15 47B34 PDFBibTeX XMLCite \textit{Semigroups Working Group at LAW'08}, Linear Algebra Appl. 433, No. 11--12, 2080--2087 (2010; Zbl 1202.47049) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena Sufficient conditions on commutators for a pair of stable matrices to have a common solution to the Lyapunov equation. (English) Zbl 1202.15018 SIAM J. Matrix Anal. Appl. 31, No. 4, 2017-2028 (2010). Reviewer: Vladimir P. Kostov (Nice) MSC: 15A24 15A04 15A21 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, SIAM J. Matrix Anal. Appl. 31, No. 4, 2017--2028 (2010; Zbl 1202.15018) Full Text: DOI
Laffey, Thomas J.; Loewy, Raphael; Šmigoc, Helena Nonnegative matrices that are similar to positive matrices. (English) Zbl 1190.15036 SIAM J. Matrix Anal. Appl. 31, No. 2, 629-649 (2009). Reviewer: Grozio Stanilov (Sofia) MSC: 15B48 15A04 PDFBibTeX XMLCite \textit{T. J. Laffey} et al., SIAM J. Matrix Anal. Appl. 31, No. 2, 629--649 (2009; Zbl 1190.15036) Full Text: DOI
Beasley, Leroy B.; Laffey, Thomas J. Real rank versus nonnegative rank. (English) Zbl 1185.15002 Linear Algebra Appl. 431, No. 12, 2330-2335 (2009). Reviewer: Rabe von Randow (Bonn) MSC: 15A03 PDFBibTeX XMLCite \textit{L. B. Beasley} and \textit{T. J. Laffey}, Linear Algebra Appl. 431, No. 12, 2330--2335 (2009; Zbl 1185.15002) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena Common Lyapunov solutions for two matrices whose difference has rank one. (English) Zbl 1170.15006 Linear Algebra Appl. 431, No. 1-2, 228-240 (2009). Reviewer: Sheng Chen (Harbin) MSC: 15A24 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Algebra Appl. 431, No. 1--2, 228--240 (2009; Zbl 1170.15006) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena On a classic example in the nonnegative inverse eigenvalue problem. (English) Zbl 1149.15008 Electron. J. Linear Algebra 17, 333-342 (2008). Reviewer: C. M. da Fonseca (Coimbra) MSC: 15A18 15B48 15A29 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Electron. J. Linear Algebra 17, 333--342 (2008; Zbl 1149.15008) Full Text: DOI EuDML EMIS Link
Laffey, Thomas J.; Šmigoc, Helena Spectra of principal submatrices of nonnegative matrices. (English) Zbl 1130.15006 Linear Algebra Appl. 428, No. 1, 230-238 (2008). Reviewer: C. M. da Fonseca (Coimbra) MSC: 15A18 15B48 15A29 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Algebra Appl. 428, No. 1, 230--238 (2008; Zbl 1130.15006) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena Construction of nonnegative symmetric matrices with given spectrum. (English) Zbl 1116.15012 Linear Algebra Appl. 421, No. 1, 97-109 (2007). Reviewer: Frank Uhlig (Auburn) MSC: 15A29 15A18 15B48 15B57 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Algebra Appl. 421, No. 1, 97--109 (2007; Zbl 1116.15012) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena Tensor conditions for the existence of a common solution to the Lyapunov equation. (English) Zbl 1162.15007 Linear Algebra Appl. 420, No. 2-3, 672-685 (2007). MSC: 15A24 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Algebra Appl. 420, No. 2--3, 672--685 (2007; Zbl 1162.15007) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena Common solution to the Lyapunov equation for \(2 \times 2\) complex matrices. (English) Zbl 1158.15303 Linear Algebra Appl. 420, No. 2-3, 609-624 (2007). Reviewer: Vladimir P. Kostov (Nice) (MR2278236) MSC: 15A24 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Algebra Appl. 420, No. 2--3, 609--624 (2007; Zbl 1158.15303) Full Text: DOI
Laffey, Thomas; Šmigoc, Helena Structured matrices in the nonnegative inverse eigenvalue problem. (English) Zbl 1180.15009 Azenhas, Olga (ed.) et al., Mathematical papers in honour of Eduardo Marques de Sá on the occasion of his 60th birthday. Coimbra: Universidade de Coimbra, Departamento de Matemática (ISBN 978-972-8564-43-8/pbk). Textos de Matemática. Série B 39, 93-106 (2006). MSC: 15A18 15A29 15B48 PDFBibTeX XMLCite \textit{T. Laffey} and \textit{H. Šmigoc}, Textos Mat., Sér. B 39, 93--106 (2006; Zbl 1180.15009)
Semitransitivity Working Group at LAW’05, Bled [Bernik, Janez; Drnovšek, Roman; Hadwin, Don; Jaffarian, Ali; Kokol Bukovšek, Damjana; Košir, Tomaž; Kramar Fijavž, Marjeta; Laffey, Thomas J.; Livshits, Leo; Mastnak, Mitja; Meshulam, Roy; Muller, Vladimir; Nordgren, Eric; Okninski, Jan; Omladič, Matjaž; Radjavi, Heydar; Sourour, Ahmed; Timoney, Richard] Semitransitive subspaces of matrices. (English) Zbl 1142.15303 Electron. J. Linear Algebra 15, 225-238 (2006). MSC: 15A30 15A21 15A09 PDFBibTeX XMLCite \textit{B. Semitransitivity Working Group at LAW'05}, Electron. J. Linear Algebra 15, 225--238 (2006; Zbl 1142.15303) Full Text: Link
Berman, Abraham; Laffey, Thomas; Leizarowitz, Arie; Shorten, Robert On the second eigenvalue of matrices associated with TCP. (English) Zbl 1101.15022 Linear Algebra Appl. 416, No. 1, 175-183 (2006). Reviewer: Huang Wenxue (Scarborough) MSC: 15B51 15A18 90B15 90B18 PDFBibTeX XMLCite \textit{A. Berman} et al., Linear Algebra Appl. 416, No. 1, 175--183 (2006; Zbl 1101.15022) Full Text: DOI
Laffey, Thomas J.; Šmigoc, Helena Nonnegative realization of spectra having negative real parts. (English) Zbl 1103.15005 Linear Algebra Appl. 416, No. 1, 148-159 (2006). Reviewer: Ralf Gramlich (Darmstadt) MSC: 15A18 15A29 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{H. Šmigoc}, Linear Algebra Appl. 416, No. 1, 148--159 (2006; Zbl 1103.15005) Full Text: DOI
Bernik, J.; Drnovšek, R.; Košir, T.; Laffey, T.; MacDonald, G.; Meshulam, R.; Omladič, M.; Radjavi, H. Common fixed points and common eigenvectors for sets of matrices. (English) Zbl 1074.15016 Linear Multilinear Algebra 53, No. 2, 137-146 (2005). Reviewer: A. A. Bogush (Minsk) MSC: 15A30 20M20 15A18 PDFBibTeX XMLCite \textit{J. Bernik} et al., Linear Multilinear Algebra 53, No. 2, 137--146 (2005; Zbl 1074.15016) Full Text: DOI
Berman, Abraham; Laffey, Thomas J. Similarity classes and principal submatrices. (English) Zbl 1088.15016 Linear Algebra Appl. 401, 341-351 (2005). Reviewer: Bambina Larato (Bari) MSC: 15A21 15A18 15A03 15B57 PDFBibTeX XMLCite \textit{A. Berman} and \textit{T. J. Laffey}, Linear Algebra Appl. 401, 341--351 (2005; Zbl 1088.15016) Full Text: DOI
Berman, Abraham (ed.); Laffey, Thomas J. (ed.) Proceedings of the 2004 workshop on nonnegative matrices, Maynooth, Ireland, July 11–14, 2004. (English) Zbl 1060.15500 Electron. J. Linear Algebra 12 (2004/2005). MSC: 15-06 00B25 PDFBibTeX XML Full Text: EuDML EMIS
Laffey, Thomas J. Perturbing non-real eigenvalues of nonnegative real matrices. (English) Zbl 1099.15007 Electron. J. Linear Algebra 12, 73-76 (2004/2005). Reviewer: Alan L. Andrew (Bundoora) MSC: 15A18 15A29 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey}, Electron. J. Linear Algebra 12, 73--76 (2004; Zbl 1099.15007) Full Text: EuDML EMIS
Laffey, Thomas; Shorten, Robert; Ó Cairbre, Fiacre On the stability of convex sums of rank-1 perturbed matrices. (English) Zbl 1089.15016 Math. Proc. R. Ir. Acad. 104A, No. 1, 99-105 (2004). Reviewer: Costică Moroşanu (Iaşi) MSC: 15A42 PDFBibTeX XMLCite \textit{T. Laffey} et al., Math. Proc. R. Ir. Acad. 104A, No. 1, 99--105 (2004; Zbl 1089.15016) Full Text: DOI
Higham, Nicholas J. (ed.); Horn, Roger (ed.); Laffey, Thomas J. (ed.); Puerta, Ferran (ed.) Proceedings of the eighth conference of the International Linear Algebra Society (ILAS), Barcelona, Spain, July 19–22, 1999. (English) Zbl 0981.00014 Linear Algebra Appl. 332-334, No. 1-3, 612 p. (2001). MSC: 00B25 15-06 65-06 PDFBibTeX XMLCite \textit{N. J. Higham} (ed.) et al., Linear Algebra Appl. 332--334, 612~p. (2001; Zbl 0981.00014) Full Text: DOI
Beasley, Leroy B.; Laffey, Thomas J. Linear preservers of matrices of rank-2. (English) Zbl 0982.15004 Linear Multilinear Algebra 48, No. 4, 319-331 (2001). Reviewer: Václav Burjan (Praha) MSC: 15A04 15B33 PDFBibTeX XMLCite \textit{L. B. Beasley} and \textit{T. J. Laffey}, Linear Multilinear Algebra 48, No. 4, 319--331 (2001; Zbl 0982.15004) Full Text: DOI
Laffey, Thomas J. Realizing matrices in the nonnegative inverse eigenvalue problem. (English) Zbl 0967.15009 Matrices and group representations. Proceedings of a workshop dedicated to Professor Graciano N. de Oliveira on the occasion of his 60th birthday, Coimbra, Portugal, May 6-8, 1998. Coimbra: Univ. de Coimbra, Departamento de Matemática. Textos Mat., Sér. B. 19, 21-32 (1999). MSC: 15A29 15A18 PDFBibTeX XMLCite \textit{T. J. Laffey}, in: Matrices and group repesentations. Proceedings of a workshop dedicated to Professor Graciano N. de Oliveira on the occasion of his 60th birthday, Coimbra, Portugal, May 6--8, 1998. Coimbra: Univ. de Coimbra, Departamento de Matemática. 21--32 (1999; Zbl 0967.15009)
Laffey, Thomas J.; Meehan, Eleanor A characterization of trace zero nonnegative \(5\times 5\) matrices. (English) Zbl 0946.15008 Linear Algebra Appl. 302-303, 295-302 (1999). Reviewer: Vaclav Burjan (Praha) MSC: 15A29 15A18 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{E. Meehan}, Linear Algebra Appl. 302--303, 295--302 (1999; Zbl 0946.15008) Full Text: DOI
Dias da Silva, J. A.; Laffey, T. J. On simultaneous similarity of matrices and related questions. (English) Zbl 0930.15012 Linear Algebra Appl. 291, No. 1-3, 167-184 (1999). Reviewer: Peter Reichensperger (Oberasbach) MSC: 15A21 PDFBibTeX XMLCite \textit{J. A. Dias da Silva} and \textit{T. J. Laffey}, Linear Algebra Appl. 291, No. 1--3, 167--184 (1999; Zbl 0930.15012) Full Text: DOI
Laffey, Thomas J. Some aspects of Olga Taussky’s work in algebra. (English) Zbl 0939.20013 Linear Algebra Appl. 280, No. 1, 51-57 (1998). Reviewer: Robert Guralnick (Los Angeles) MSC: 20D15 15A22 20-03 15-03 01A70 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 280, No. 1, 51--57 (1998; Zbl 0939.20013) Full Text: DOI
Laffey, Thomas J. Extreme nonnegative matrices. (English) Zbl 0933.15028 Linear Algebra Appl. 275-276, 349-357 (1998). MSC: 15A29 15A18 15B48 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 275--276, 349--357 (1998; Zbl 0933.15028) Full Text: DOI
Laffey, Thomas J. Expressing unipotent matrices over rings as products of involutions. (English) Zbl 0910.15001 Ir. Math. Soc. Bull. 40, 24-30 (1998). Reviewer: W.H.Gustafson (Lubbock) MSC: 15A23 20G35 PDFBibTeX XMLCite \textit{T. J. Laffey}, Ir. Math. Soc. Bull. 40, 24--30 (1998; Zbl 0910.15001)
Laffey, Thomas J.; Meehan, Eleanor A refinement of an inequality of Johnson, Loewy and London on nonnegative matrices and some applications. (English) Zbl 0907.15013 Electron. J. Linear Algebra 3, 119-128 (1998). Reviewer: J.M.Day (San José) MSC: 15A45 15B48 15A18 05C50 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{E. Meehan}, Electron. J. Linear Algebra 3, 119--128 (1998; Zbl 0907.15013) Full Text: DOI EuDML EMIS
Laffey, Thomas J. A sparsity result on nonnegative real matrices with given spectrum. (English) Zbl 0877.15025 Janas, Jan (ed.) et al., Linear operators. Proceedings of the semester organized at the Stefan Banach International Mathematical Center, Warsaw, Poland, February 7–May 15, 1994. Warsaw: Polish Academy of Sciences, Inst. of Mathematics, Banach Cent. Publ. 38, 187-191 (1997). MSC: 15B48 15A18 PDFBibTeX XMLCite \textit{T. J. Laffey}, Banach Cent. Publ. 38, 187--191 (1997; Zbl 0877.15025) Full Text: EuDML
Johnson, Charles R.; Laffey, Thomas J.; Loewy, Raphael The real and the symmetric nonnegative inverse eigenvalue problems are different. (English) Zbl 0861.15007 Proc. Am. Math. Soc. 124, No. 12, 3647-3651 (1996). MSC: 15A18 15B48 PDFBibTeX XMLCite \textit{C. R. Johnson} et al., Proc. Am. Math. Soc. 124, No. 12, 3647--3651 (1996; Zbl 0861.15007) Full Text: DOI
Laffey, Thomas J. Inverse eigenvalue problems for matrices. (English) Zbl 1280.15005 Proc. R. Ir. Acad., Sect. A 95, Suppl., 81-88 (1995). MSC: 15A18 PDFBibTeX XMLCite \textit{T. J. Laffey}, Proc. R. Ir. Acad., Sect. A 95, 81--88 (1995; Zbl 1280.15005)
Laffey, Thomas J. Conjugacy and factorization results on matrix groups. (English) Zbl 0802.15008 Zemánek, Jaroslav (ed.), Functional analysis and operator theory. Proceedings of the 39th semester at the Stefan Banach International Mathematical Center in Warsaw, Poland, held March 2-May 30, 1992. Warsaw: Polish Academy of Sciences, Banach Cent. Publ. 30, 203-221 (1994). MSC: 15B33 15-02 15A23 15B36 PDFBibTeX XMLCite \textit{T. J. Laffey}, Banach Cent. Publ. 30, 203--221 (1994; Zbl 0802.15008)
Laffey, Thomas J.; Reams, Robert Integral similarity and commutators of integral matrices. (English) Zbl 0801.15015 Linear Algebra Appl. 197-198, 671-689 (1994). Reviewer: N.Backhouse (Liverpool) MSC: 15B36 15A27 15A21 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{R. Reams}, Linear Algebra Appl. 197--198, 671--689 (1994; Zbl 0801.15015) Full Text: DOI
Laffey, Thomas J.; Meehan, Eleanor Factorization of polynomials using commuting matrices. (English) Zbl 0789.15011 Linear Algebra Appl. 196, 85-103 (1994). Reviewer: Li Fang (Nanjing) MSC: 15A23 12D05 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{E. Meehan}, Linear Algebra Appl. 196, 85--103 (1994; Zbl 0789.15011) Full Text: DOI
Laffey, T. J.; West, T. T. Trace-zero matrices and polynomial commutators. (English) Zbl 0804.15009 Ir. Math. Soc. Bull. 31, 11-13 (1993). Reviewer: Chen Zhijie (Shanghai) MSC: 15A27 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{T. T. West}, Ir. Math. Soc. Bull. 31, 11--13 (1993; Zbl 0804.15009)
Laffey, Thomas J.; Meehan, Eleanor Factorization of polynomials using nilpotent Jordan blocks. (English) Zbl 0755.15005 Appl. Math. Lett. 5, No. 4, 29-33 (1992). MSC: 15A23 15A54 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{E. Meehan}, Appl. Math. Lett. 5, No. 4, 29--33 (1992; Zbl 0755.15005) Full Text: DOI
Laffey, Thomas J.; Meehan, Eleanor An extension of a factorization theorem of Wedderburn to matrix rings. (English) Zbl 0760.15009 Linear Algebra Appl. 172, 243-260 (1992). Reviewer: E.Ellers (Toronto) MSC: 15A30 15A23 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{E. Meehan}, Linear Algebra Appl. 172, 243--260 (1992; Zbl 0760.15009) Full Text: DOI
Laffey, Thomas J. A structure theorem for some matrix algebras. (English) Zbl 0758.16010 Linear Algebra Appl. 162-164, 205-215 (1992). Reviewer: K.Mathiak (Braunschweig) MSC: 16S50 15A18 15A30 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 162--164, 205--215 (1992; Zbl 0758.16010) Full Text: DOI Backlinks: MO
Laffey, Thomas J. Products of matrices. (English) Zbl 0729.15012 Generators and relations in groups and geometries, Proc. NATO/ASI, Castelvecchio-Pascoli/Italy 1990, NATO ASI Ser., Ser. C 333, 95-123 (1991). Reviewer: E.Ellers (Toronto) MSC: 15A23 20H20 15B36 PDFBibTeX XML
Laffey, Thomas J.; Lazarus, Susan Two-generated commutative matrix subalgebras. (English) Zbl 0718.15008 Linear Algebra Appl. 147, 249-273 (1991). Reviewer: T.B.Andersen (Aarhus) MSC: 15A30 15A27 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{S. Lazarus}, Linear Algebra Appl. 147, 249--273 (1991; Zbl 0718.15008) Full Text: DOI
Beasley, LeRoy B.; Laffey, Thomas J. Linear operators on matrices: The invariance of rank-k matrices. (English) Zbl 0721.15006 Linear Algebra Appl. 133, 175-184 (1990). Reviewer: S.Sridhar (Madras) MSC: 15A30 PDFBibTeX XMLCite \textit{L. B. Beasley} and \textit{T. J. Laffey}, Linear Algebra Appl. 133, 175--184 (1990; Zbl 0721.15006) Full Text: DOI
Laffey, Thomas J.; Loewy, Raphael Linear transformations which do not increase rank. (English) Zbl 0697.15004 Linear Multilinear Algebra 26, No. 3, 181-186 (1990). Reviewer: R.Ursianu MSC: 15A04 15A30 15A03 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{R. Loewy}, Linear Multilinear Algebra 26, No. 3, 181--186 (1990; Zbl 0697.15004) Full Text: DOI
Laffey, T. J. Matrix factorization with symmetry properties. (English) Zbl 0711.15011 Applications of matrix theory, Proc. Conf., Bradford/UK 1988, Inst. Math. Appl. Conf. Ser., New Ser. 22, 63-70 (1989). Reviewer: F.Juhász MSC: 15A23 PDFBibTeX XML
Laffey, Thomas J. Factorizations of integer matrices as products of idempotents and nilpotents. (English) Zbl 0677.15005 Linear Algebra Appl. 120, 81-93 (1989). Reviewer: Huberta Lausch MSC: 15B36 15A23 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 120, 81--93 (1989; Zbl 0677.15005) Full Text: DOI
Johnson, Charles R.; Laffey, Thomas; Li, Chi-Kwong Linear transformations on \(M_ n({\mathbb{R}})\) that preserve the Ky Fan k- norm and a remarkable special case when \((n,k)=(4,2)\). (English) Zbl 0658.15029 Linear Multilinear Algebra 23, No. 4, 285-298 (1988). Reviewer: A.A.Jafarian MSC: 15A60 15A04 15A21 15A18 PDFBibTeX XMLCite \textit{C. R. Johnson} et al., Linear Multilinear Algebra 23, No. 4, 285--298 (1988; Zbl 0658.15029) Full Text: DOI
Laffey, Thomas J. Factorizations of matrices involving symmetric matrices and involutions. (English) Zbl 0654.15004 Current trends in matrix theory, Proc. 3rd Conf., Auburn/Ala. 1986, 175-198 (1987). MSC: 15A23 15A30 PDFBibTeX XML
Laffey, Thomas J. Simultaneous reduction of sets of matrices under similarity. (English) Zbl 0609.15004 Linear Algebra Appl. 84, 123-138 (1986). Reviewer: G.P.Barker MSC: 15A21 15A30 16S50 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 84, 123--138 (1986; Zbl 0609.15004) Full Text: DOI
Laffey, Thomas J. On a question of Hills concerning co-transposers. (English) Zbl 0591.15006 Port. Math. 43(1985/86), 179-187 (1986). MSC: 15A21 15A30 PDFBibTeX XMLCite \textit{T. J. Laffey}, Port. Math. 43, 179--187 (1986; Zbl 0591.15006) Full Text: EuDML
Laffey, Thomas J. The minimal dimension of maximal commutative subalgebras of full matrix algebras. (English) Zbl 0578.15008 Linear Algebra Appl. 71, 199-212 (1985). Reviewer: K.Yamaguti MSC: 15A30 16S50 16P10 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 71, 199--212 (1985; Zbl 0578.15008) Full Text: DOI
Gaines, F. J.; Laffey, T. J. Report on the Dublin Matrix Theory Conference, March 1984. (English) Zbl 0578.15001 Linear Algebra Appl. 68, 243-274 (1985). MSC: 15-06 00Bxx 15B33 15A30 15A23 15A15 15B57 65F50 15A24 PDFBibTeX XMLCite \textit{F. J. Gaines} and \textit{T. J. Laffey}, Linear Algebra Appl. 68, 243--274 (1985; Zbl 0578.15001) Full Text: DOI
Gow, R.; Laffey, T. J. Pairs of alternating forms and products of two skew-symmetric matrices. (English) Zbl 0557.15016 Linear Algebra Appl. 63, 119-132 (1984). Reviewer: F.Uhlig MSC: 15B57 15A21 15A23 PDFBibTeX XMLCite \textit{R. Gow} and \textit{T. J. Laffey}, Linear Algebra Appl. 63, 119--132 (1984; Zbl 0557.15016) Full Text: DOI
Laffey, Thomas J. A characterisation of full matrix algebras. (English) Zbl 0536.15006 Linear Multilinear Algebra 15, 105-108 (1984). Reviewer: J.D.Dixon MSC: 15A30 16U99 16P10 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Multilinear Algebra 15, 105--108 (1984; Zbl 0536.15006) Full Text: DOI
Laffey, Thomas J. A counterexample to Kippenhahn’s conjecture on Hermitian pencils. (English) Zbl 0539.15004 Linear Algebra Appl. 51, 179-182 (1983). Reviewer: M.E.Sezer MSC: 15A21 15B57 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 51, 179--182 (1983; Zbl 0539.15004) Full Text: DOI
Laffey, Thomas J. Van der Waerden’s conjecture on permanents and its resolution. (English) Zbl 0531.15004 Ir. Math. Soc. Newsl. 9, 28-40 (1983). Reviewer: R.Sinkhorn MSC: 15A15 15B51 15A45 PDFBibTeX XMLCite \textit{T. J. Laffey}, Ir. Math. Soc. Newsl. 9, 28--40 (1983; Zbl 0531.15004)
Laffey, Thomas J. Products of idempotent matrices. (English) Zbl 0526.15008 Linear Multilinear Algebra 14, 309-314 (1983). MSC: 15A23 15B33 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Multilinear Algebra 14, 309--314 (1983; Zbl 0526.15008) Full Text: DOI
Hannah, John; Laffey, Thomas J. Nonnegative factorization of completely positive matrices. (English) Zbl 0519.15007 Linear Algebra Appl. 55, 1-9 (1983). MSC: 15B48 15A23 15A63 PDFBibTeX XMLCite \textit{J. Hannah} and \textit{T. J. Laffey}, Linear Algebra Appl. 55, 1--9 (1983; Zbl 0519.15007) Full Text: DOI
Gaines, Fergus J.; Laffey, Thomas J.; Shapiro, Helene M. Pairs of matrices with quadratic minimal polynomials. (English) Zbl 0515.15006 Linear Algebra Appl. 52-53, 289-292 (1983). MSC: 15A30 16S50 16P10 15A21 PDFBibTeX XMLCite \textit{F. J. Gaines} et al., Linear Algebra Appl. 52--53, 289--292 (1983; Zbl 0515.15006) Full Text: DOI
Laffey, Thomas J. A criterion for generating full matrix algebras. (English) Zbl 0462.16012 Linear Algebra Appl. 37, 191-198 (1981). MSC: 16S50 15A30 16D70 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 37, 191--198 (1981; Zbl 0462.16012) Full Text: DOI
Laffey, Thomas J. A note on matrix subalgebras containing a full Jordan block. (English) Zbl 0462.16011 Linear Algebra Appl. 37, 187-189 (1981). MSC: 16S50 15A30 16D70 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 37, 187--189 (1981; Zbl 0462.16011) Full Text: DOI
Laffey, Thomas J. Algebras generated by two idempotents. (English) Zbl 0459.16010 Linear Algebra Appl. 37, 45-53 (1981). MSC: 16U99 16D70 16P10 16S50 16Kxx 15B33 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 37, 45--53 (1981; Zbl 0459.16010) Full Text: DOI
Laffey, Thomas J. Simultaneous triangularization of a pair of matrices whose commutator has rank two. (English) Zbl 0432.15007 Linear Algebra Appl. 29, 195-203 (1980). MSC: 15A21 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 29, 195--203 (1980; Zbl 0432.15007) Full Text: DOI
Laffey, Thomas J. A basis theorem for matrix algebras. (English) Zbl 0428.15007 Linear Multilinear Algebra 8, 183-187 (1980). MSC: 15A24 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Multilinear Algebra 8, 183--187 (1980; Zbl 0428.15007) Full Text: DOI
Laffey, Thomas J. A normality criterion for an algebra of matrices. (English) Zbl 0401.15013 Linear Algebra Appl. 25, 169-174 (1979). MSC: 15A30 15A27 15A24 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 25, 169--174 (1979; Zbl 0401.15013) Full Text: DOI
Laffey, Thomas J. Simultaneous triangularization of matrices – low rank cases and the nonderogatory case. (English) Zbl 0399.15008 Linear Multilinear Algebra 6, 269-305 (1978). MSC: 15A21 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Multilinear Algebra 6, 269--305 (1978; Zbl 0399.15008) Full Text: DOI
Laffey, Thomas J. Simultaneous quasidiagonalization of a pair of \(3\times 3\) complex matrices. (English) Zbl 0397.15009 Rev. Roum. Math. Pures Appl. 23, 1047-1052 (1978). MSC: 15A21 PDFBibTeX XMLCite \textit{T. J. Laffey}, Rev. Roum. Math. Pures Appl. 23, 1047--1052 (1978; Zbl 0397.15009)
Laffey, T. J. Finite groups generated by a pair of unitary matrices with normal sum. (English) Zbl 0364.15016 Proc. R. IR. Acad., Sect. A 77, 61-74 (1977). MSC: 15B57 20K99 PDFBibTeX XML
Laffey, Thomas J. Simultaneous quasidiagonalization of complex matrices. (English) Zbl 0353.15030 Linear Algebra Appl. 16, 189-201 (1977). MSC: 15B57 15A21 PDFBibTeX XMLCite \textit{T. J. Laffey}, Linear Algebra Appl. 16, 189--201 (1977; Zbl 0353.15030) Full Text: DOI
Laffey, Thomas J. Simultaneous triangularization of a pair of matrices. (English) Zbl 0348.15006 J. Algebra 44, 550-557 (1977). MSC: 15A21 15-00 PDFBibTeX XMLCite \textit{T. J. Laffey}, J. Algebra 44, 550--557 (1977; Zbl 0348.15006) Full Text: DOI
Laffey, Thomas J.; McQuillan, Donald L. A note on subfields of matrix rings. (English) Zbl 0345.16025 Linear Algebra Appl. 16, 1-3 (1977). MSC: 16S50 16D70 15B33 PDFBibTeX XMLCite \textit{T. J. Laffey} and \textit{D. L. McQuillan}, Linear Algebra Appl. 16, 1--3 (1977; Zbl 0345.16025) Full Text: DOI
Gaines, F. J.; Laffey, T. J. Permutation matrices with normal sum. (English) Zbl 0288.15021 Proc. R. Ir. Acad., Sect. A 75, 227-254 (1975). MSC: 15A30 15A18 20B99 PDFBibTeX XMLCite \textit{F. J. Gaines} and \textit{T. J. Laffey}, Proc. R. Ir. Acad., Sect. A 75, 227--254 (1975; Zbl 0288.15021)