All Stories

  1. Determinantal representations for the number of subsequences without isolated odd terms

    Article • Notes on Number Theory and Discrete Mathematics, December 2021, Prof. Marin Drinov Academic Publishing House

    Prof. Carlos M. da Fonseca

  2. A periodic determinantal property for (0,1) double banded matrices

    Article • Linear and Multilinear Algebra, April 2021, Taylor & Francis

    Prof. Carlos M. da Fonseca

  3. Three Representation Types for Systems of Forms and Linear Maps

    Article • Mathematics, February 2021, MDPI AG

    Prof. Carlos M. da Fonseca

  4. Comments on the spectrum of a tridiagonal k-Toeplitz matrix

    Article • Journal of Computational and Applied Mathematics, September 2020, Elsevier

    Prof. Carlos M. da Fonseca

  5. On a closed form for derangement numbers: an elementary proof

    Article • Revista de la Real Academia de Ciencias Exactas Físicas y Naturales Serie A Matemáticas, June 2020, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  6. On nonsingular acyclic M-matrices whose inverse is also acyclic

    Article • Revista de la Real Academia de Ciencias Exactas Físicas y Naturales Serie A Matemáticas, May 2020, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  7. A Short Note on the Determinant of a Sylvester–Kac Type Matrix

    Article • International Journal of Nonlinear Sciences and Numerical Simulation, February 2020, De Gruyter

    Prof. Carlos M. da Fonseca

  8. A matrix approach to some second-order difference equations with sign-alternating coefficients

    Article • The Journal of Difference Equations and Applications, January 2020, Taylor & Francis

    Prof. Carlos M. da Fonseca

  9. Some determinantal considerations for pentadiagonal matrices

    Article • Linear and Multilinear Algebra, January 2020, Taylor & Francis

    Prof. Carlos M. da Fonseca

  10. Eigenpairs of some particular band Toeplitz matrices: A comment

    Article • Numerical Linear Algebra with Applications, October 2019, Wiley

    Prof. Carlos M. da Fonseca

  11. Line and Subdivision Graphs Determined by T4-Gain Graphs

    Article • Mathematics, October 2019, MDPI AG

    Prof. Carlos M. da Fonseca

  12. Eigenpairs of a family of tridiagonal matrices: three decades later

    Article • Acta Mathematica Hungarica, September 2019, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  13. On the continuity of the maximum size of P-sets of acyclic matrices

    Article • Discrete Mathematics, August 2019, Elsevier

    Prof. Carlos M. da Fonseca

  14. Some comments on tridiagonal (p,r)-Toeplitz matrices

    Article • Linear Algebra and its Applications, July 2019, Elsevier

    Prof. Carlos M. da Fonseca

  15. Lipschitz property for systems of linear mappings and bilinear forms

    Article • Linear Algebra and its Applications, July 2019, Elsevier

    Prof. Carlos M. da Fonseca

  16. A new type of Sylvester–Kac matrix and its spectrum

    Article • Linear and Multilinear Algebra, May 2019, Taylor & Francis

    Prof. Carlos M. da Fonseca

  17. Remarks on the eigenpairs of some Jacobi matrices

    Article • Filomat, January 2019, National Library of Serbia

    Prof. Carlos M. da Fonseca

  18. On some conjectures regarding tridiagonal matrices

    Article • Journal of Applied Mathematics and Computational Mechanics, December 2018, Czestochowa University of Technology

    Prof. Carlos M. da Fonseca

  19. Vertex types in some lexicographic products of graphs

    Article • Linear and Multilinear Algebra, July 2018, Taylor & Francis

    Prof. Carlos M. da Fonseca

  20. The minimal-ABC trees with B1-branches

    Article • PLoS ONE, April 2018, PLOS

    Prof. Carlos M. da Fonseca

  21. Some forbidden combinations of branches in minimal-ABC trees

    Article • Discrete Applied Mathematics, February 2018, Elsevier

    Prof. Carlos M. da Fonseca

  22. Generalized cosecant numbers and trigonometric inverse power sums

    Article • Applicable Analysis and Discrete Mathematics, January 2018, National Library of Serbia

    Prof. Carlos M. da Fonseca

  23. Topological classification of systems of bilinear and sesquilinear forms

    Article • Linear Algebra and its Applications, February 2017, Elsevier

    Prof. Carlos M. da Fonseca

  24. Some spectral bounds for the harmonic matrix

    Article • Analele Universitatii Ovidius Constanta - Seria Matematica, January 2017, De Gruyter

    Prof. Carlos M. da Fonseca

  25. Classification of pairs of linear mappings between two vector spaces and between their quotient space and subspace

    Article • Linear Algebra and its Applications, November 2016, Elsevier

    Prof. Carlos M. da Fonseca

  26. Topological classification of sesquilinear forms: Reduction to the nonsingular case

    Article • Linear Algebra and its Applications, September 2016, Elsevier

    Prof. Carlos M. da Fonseca

  27. The real symmetric matrices of odd order with a P-set of maximum size

    Article • Czechoslovak Mathematical Journal, September 2016, Institute of Mathematics, Czech Academy of Sciences

    Prof. Carlos M. da Fonseca

  28. On structural properties of trees with minimal atom-bond connectivity index III: Trees with pendent paths of length three

    Article • Applied Mathematics and Computation, May 2016, Elsevier

    Prof. Carlos M. da Fonseca

  29. Basic trigonometric power sums with applications

    Article • The Ramanujan Journal, March 2016, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  30. Class of cooperative stochastic models: Exact and approximate solutions, simulations, and experiments using ionic self-assembly of nanoparticles

    Article • March 2016, American Physical Society (APS)

    Prof. Carlos M. da Fonseca

  31. On a family of trees with minimal atom-bond connectivity index

    Article • Discrete Applied Mathematics, March 2016, Elsevier

    Prof. Carlos M. da Fonseca

  32. Bruhat rank

    Article • Open Mathematics, January 2016, De Gruyter

    Prof. Carlos M. da Fonseca

  33. The singular acyclic matrices of even order with a P-set of maximum size

    Article • Filomat, January 2016, National Library of Serbia

    Prof. Carlos M. da Fonseca

  34. On Singular Values Related to DAEs in Kronecker Canonical Form

    Article • Mediterranean Journal of Mathematics, November 2015, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  35. Some comments on k -tridiagonal matrices: Determinant, spectra, and inversion

    Article • Applied Mathematics and Computation, November 2015, Elsevier

    Prof. Carlos M. da Fonseca

  36. Reflexive line graphs of trees

    Article • Journal of Algebraic Combinatorics, October 2015, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  37. Some new considerations about double nested graphs

    Article • Linear Algebra and its Applications, October 2015, Elsevier

    Prof. Carlos M. da Fonseca

  38. Eigenvalues of a certain class of tridiagonal matrices: A brief comment

    Article • Applied Mathematics and Computation, July 2015, Elsevier

    Prof. Carlos M. da Fonseca

  39. A multi-temperature kinetic Ising model and the eigenvalues of some perturbed Jacobi matrices

    Article • Applied Mathematics and Computation, May 2015, Elsevier

    Prof. Carlos M. da Fonseca

  40. The acyclic matrices with a P-set of maximum size

    Article • Linear Algebra and its Applications, March 2015, Elsevier

    Prof. Carlos M. da Fonseca

  41. Notes on the second largest eigenvalue of a graph

    Article • Linear Algebra and its Applications, January 2015, Elsevier

    Prof. Carlos M. da Fonseca

  42. The singular acyclic matrices with the second largest number of P-vertices

    Article • Linear and Multilinear Algebra, October 2014, Taylor & Francis

    Prof. Carlos M. da Fonseca

  43. Young-type inequalities and their matrix analogues

    Article • Linear and Multilinear Algebra, June 2014, Taylor & Francis

    Prof. Carlos M. da Fonseca

  44. Unifying some Pell and Fibonacci identities

    Article • Applied Mathematics and Computation, June 2014, Elsevier

    Prof. Carlos M. da Fonseca

  45. Nonsingular acyclic matrices with an extremal number of P-vertices

    Article • Linear Algebra and its Applications, February 2014, Elsevier

    Prof. Carlos M. da Fonseca

  46. Advances in Matrices, Finite and Infinite, with Applications 2014

    Article • Journal of Applied Mathematics, January 2014, Hindawi Publishing Corporation

    Prof. Carlos M. da Fonseca

  47. The eigenvalues of a family of persymmetric anti-tridiagonal 2-Hankel matrices

    Article • Applied Mathematics and Computation, December 2013, Elsevier

    Prof. Carlos M. da Fonseca

  48. The eigenpairs of a Sylvester–Kac type matrix associated with a simple model for one-dimensional deposition and evaporation

    Article • Applied Mathematics Letters, December 2013, Elsevier

    Prof. Carlos M. da Fonseca

  49. The maximum number of P-vertices of some nonsingular double star matrices

    Article • Discrete Mathematics, October 2013, Elsevier

    Prof. Carlos M. da Fonseca

  50. Nonsingular acyclic matrices with full number of P-vertices

    Article • Linear and Multilinear Algebra, August 2013, Taylor & Francis

    Prof. Carlos M. da Fonseca

  51. Remarks and open problems on the minimum permanent of acyclic doubly stochastic matrices

    Article • Linear and Multilinear Algebra, March 2013, Taylor & Francis

    Prof. Carlos M. da Fonseca

  52. The singular acyclic matrices with maximal number of P-vertices

    Article • Linear Algebra and its Applications, March 2013, Elsevier

    Prof. Carlos M. da Fonseca

  53. Nonsingular acyclic matrices with full number of P-vertices

    Article • Linear and Multilinear Algebra, January 2013, Taylor & Francis

    Prof. Carlos M. da Fonseca

  54. On a finite sum with powers of cosines

    Article • Applicable Analysis and Discrete Mathematics, January 2013, National Library of Serbia

    Prof. Carlos M. da Fonseca

  55. Some consequences of an inequality on the spectral multiplicity of graphs

    Article • Filomat, January 2013, National Library of Serbia

    Prof. Carlos M. da Fonseca

  56. Some further bounds for the Q-index of nested split graphs

    Article • Journal of Mathematical Sciences, March 2012, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  57. Connected graphs of fixed order and size with maximal

    Article • Discrete Applied Mathematics, March 2012, Elsevier

    Prof. Carlos M. da Fonseca

  58. Preface to the proceedings of the Coimbra meeting on 0–1 matrix theory and related topics

    Article • Linear Algebra and its Applications, February 2012, Elsevier

    Prof. Carlos M. da Fonseca

  59. The maximal length of a chain in the Bruhat order for a class of binary matrices

    Article • Linear Algebra and its Applications, February 2012, Elsevier

    Prof. Carlos M. da Fonseca

  60. On the rank spread of graphs

    Article • Linear and Multilinear Algebra, January 2012, Taylor & Francis

    Prof. Carlos M. da Fonseca

  61. On the Largest Size of an Antichain in the Bruhat Order for

    Article • Order, December 2011, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  62. An identity between the determinant and the permanent of Hessenberg-type matrices

    Article • Czechoslovak Mathematical Journal, December 2011, Institute of Mathematics, Czech Academy of Sciences

    Prof. Carlos M. da Fonseca

  63. New permanental bounds for Ferrers matrices

    Article • Linear Algebra and its Applications, December 2011, Elsevier

    Prof. Carlos M. da Fonseca

  64. On bounds for the index of double nested graphs

    Article • Linear Algebra and its Applications, November 2011, Elsevier

    Prof. Carlos M. da Fonseca

  65. An inverse eigenvalue problem for periodic Jacobi matrices in Minkowski spaces

    Article • Linear Algebra and its Applications, October 2011, Elsevier

    Prof. Carlos M. da Fonseca

  66. Some open questions on the Fibonacci polytope

    Article • Linear and Multilinear Algebra, March 2011, Taylor & Francis

    Prof. Carlos M. da Fonseca

  67. On the number of P-vertices of some graphs

    Article • Linear Algebra and its Applications, January 2011, Elsevier

    Prof. Carlos M. da Fonseca

  68. Sufficient conditions for positive definiteness of tridiagonal matrices revisited

    Article • Positivity, February 2010, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  69. The

    Article • Linear Algebra and its Applications, February 2010, Elsevier

    Prof. Carlos M. da Fonseca

  70. Cover matrices of posets and their spectra

    Article • Czechoslovak Mathematical Journal, November 2009, Institute of Mathematics, Czech Academy of Sciences

    Prof. Carlos M. da Fonseca

  71. On the spectra of certain directed paths

    Article • Applied Mathematics Letters, September 2009, Elsevier

    Prof. Carlos M. da Fonseca

  72. The number of faces of the tridiagonal Birkhoff polytope

    Article • Journal of Mathematical Sciences, September 2009, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  73. On (0, 1)-matrices with prescribed row and column sum vectors

    Article • Discrete Mathematics, April 2009, Elsevier

    Prof. Carlos M. da Fonseca

  74. Face counting on an Acyclic Birkhoff polytope

    Article • Linear Algebra and its Applications, February 2009, Elsevier

    Prof. Carlos M. da Fonseca

  75. Fibonacci numbers, alternating parity sequences and faces of the tridiagonal Birkhoff polytope

    Article • Discrete Mathematics, April 2008, Elsevier

    Prof. Carlos M. da Fonseca

  76. The diameter of the acyclic Birkhoff polytope

    Article • Linear Algebra and its Applications, April 2008, Elsevier

    Prof. Carlos M. da Fonseca

  77. On the multiplicities of eigenvalues of a Hermitian matrix whose graph is a tree

    Article • Annali di Matematica Pura ed Applicata (1923 -), October 2007, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  78. On the eigenvalues of some tridiagonal matrices

    Article • Journal of Computational and Applied Mathematics, March 2007, Elsevier

    Prof. Carlos M. da Fonseca

  79. An interlacing theorem for matrices whose graph is a given tree

    Article • Journal of Mathematical Sciences, December 2006, Springer Science + Business Media

    Prof. Carlos M. da Fonseca

  80. On the location of the eigenvalues of Jacobi matrices

    Article • Applied Mathematics Letters, November 2006, Elsevier

    Prof. Carlos M. da Fonseca

  81. On the inertia sets of some symmetric sign patterns

    Article • Czechoslovak Mathematical Journal, September 2006, Institute of Mathematics, Czech Academy of Sciences

    Prof. Carlos M. da Fonseca

  82. A note on the multiplicities of the eigenvalues of a graph

    Article • Linear and Multilinear Algebra, July 2005, Taylor & Francis

    Prof. Carlos M. da Fonseca

  83. On a conjecture about the μ-permanent

    Article • Linear and Multilinear Algebra, June 2005, Taylor & Francis

    Prof. Carlos M. da Fonseca

  84. A note on the spectra of tridiagonal matrices

    Article • International Journal of Mathematics and Mathematical Sciences, January 2004, Hindawi Publishing Corporation

    Prof. Carlos M. da Fonseca

  85. Explicit inverses of some tridiagonal matrices

    Article • Linear Algebra and its Applications, March 2001, Elsevier

    Prof. Carlos M. da Fonseca