Research Interests

Matrix and Operator Theory

Publications

1. 1)Helena Šmigoc. The inverse eigenvalue problem for nonnegative matrices. Linear Algebra Appl., 393:365–374, 2004. ISSN 0024-3795.
   

2. 2)Helena Šmigoc. Construction of nonnegative matrices and the inverse eigenvalue problem. Linear Multilinear Algebra, 53(2):85–96, 2005. ISSN 0308-1087.
   

3. 3)Thomas J. Laffey and Helena Šmigoc. Nonnegative realization of spectra having negative real parts. Linear Algebra Appl., 416(1):148–159, 2006a. ISSN 0024-3795.
   

4. 4)Thomas Laffey and Helena Šmigoc. Structured matrices in the nonnegative inverse eigenvalue problem. In Mathematical papers in honour of Eduardo Marques de Sá, volume 39 of Textos Mat. Sér. B, pages 93–106. Univ. Coimbra, Coimbra, 2006b.
   

5. 5)Thomas J. Laffey and Helena Šmigoc. Common solution to the Lyapunov equation for 2 × 2 complex matrices. Linear Algebra Appl., 420(2-3):609–624, 2007a. ISSN 0024-3795.
   

6. 6)Thomas J. Laffey and Helena Šmigoc. Tensor conditions for the existence of a common solution to the Lyapunov equation. Linear Algebra Appl., 420(2-3): 672–685, 2007b. ISSN 0024-3795.
   

7. 7)Thomas J. Laffey and Helena Šmigoc. Construction of nonnegative symmetric matrices with given spectrum. Linear Algebra Appl., 421(1):97–109, 2007c. ISSN 0024-3795.
   

8. 8)Thomas J. Laffey and Helena Šmigoc. Spectra of principal submatrices of nonnegative matrices. Linear Algebra Appl., 428(1):230–238, 2008a. ISSN 0024-3795.
   

9. 9)Thomas J. Laffey and Helena Šmigoc. On a classic example in the nonnegative inverse eigenvalue problem. Electron. J. Linear Algebra, 17:333–342, 2008b. ISSN 1081-3810.
   

10. 10)Thomas J. Laffey and Helena Šmigoc. Common Lyapunov solutions for two matrices whose difference has rank one. Linear Algebra Appl., 431(1-2): 228–240, 2009. ISSN 0024-3795. doi: 10.1016/j.laa.2009.02.026. URL http://dx.doi.org/10.1016/j.laa.2009.02.026.
    

11. 11)Thomas J. Laffey, Raphael Loewy, and Helena Šmigoc. Nonnegative matrices that are similar to positive matrices. SIAM J. Matrix Anal. Appl., 31(2):629–649, 2009. ISSN 0895-4798. doi: 10.1137/070692807. URL http://dx.doi.org/10.1137/070692807.
    

12. 12)Thomas J. Laffey and Helena Šmigoc. Nonnegatively realizable spectra with two positive eigenvalues. Linear Multilinear Algebra, 58(7-8):1053– 1069, 2010. ISSN 0308-1087. doi: 10.1080/03081080903278842. URL http://dx.doi.org/10.1080/03081080903278842.
    

13. 13)Alberto Borobia, Roberto Canogar, and Helena Šmigoc. A matrix completion problem over integral domains: the case with 2n − 3 prescribed entries. Linear Algebra Appl., 433(3):606–617, 2010. ISSN 0024-3795. doi: 10.1016/j.laa.2010.03.025. URL http://dx.doi.org/10.1016/j.laa.2010.03.025.
    

14. 14)Thomas J. Laffey and Helena Šmigoc. Sufficient conditions on commutators for a pair of stable matrices to have a common solution to the Lyapunov equation. SIAM J. Matrix Anal. Appl., 31(4):2017–2028, 2009/10. ISSN 0895-4798. doi:10.1137/070695289. URL http://dx.doi.org/10.1137/070695289.