Zobrazeno 1 - 10
of 225
pro vyhledávání: '"da Fonseca Carlos M."'
Autor:
da Fonseca Carlos M., Kowalenko Victor
Publikováno v:
Acta Universitatis Sapientiae: Mathematica, Vol 14, Iss 1, Pp 61-74 (2022)
This paper aims to show how some standard general results can be used to uncover the spectral theory of tridiagonal and related matrices more elegantly and simply than existing approaches. As a typical example, we apply the theory to the special trid
Externí odkaz:
https://doaj.org/article/b1d3c10f1b154d9388777d0995982f0d
Publikováno v:
Open Mathematics, Vol 19, Iss 1, Pp 505-514 (2021)
In this paper, we disprove a remaining conjecture about Bohemian matrices, in which the numbers of distinct determinants of a normalized Bohemian upper-Hessenberg matrix were conjectured.
Externí odkaz:
https://doaj.org/article/7618503d50804d45b21c25ada4105938
Autor:
da Fonseca Carlos M.
Publikováno v:
Acta Universitatis Sapientiae: Mathematica, Vol 12, Iss 2, Pp 280-286 (2020)
In this note, we recall several connections between the determinant of some tridiagonal matrices and the orthogonal polynomials allowing the relation between Chebyshev polynomials of second kind and Fibonacci numbers. With basic transformations, we a
Externí odkaz:
https://doaj.org/article/f0c0576bf25946409a9096ffc6cce234
Autor:
Du Zhibin, da Fonseca Carlos M.
Publikováno v:
Discussiones Mathematicae Graph Theory, Vol 40, Iss 2, Pp 525-532 (2020)
Let A be a real symmetric matrix. If after we delete a row and a column of the same index, the nullity increases by one, we call that index a P-vertex of A. When A is an n × n singular acyclic matrix, it is known that the maximum number of P-vertice
Externí odkaz:
https://doaj.org/article/313ad6779cc04528bd60729f0c41a1a3
Autor:
da Fonseca Carlos M., Kılıç Emrah
Publikováno v:
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, Vol 28, Iss 1, Pp 111-115 (2020)
Based on a less-known result, we prove a recent conjecture concerning the determinant of a certain Sylvester-Kac type matrix related to some Lie Algebras. The determinant of an extension of that matrix is presented.
Externí odkaz:
https://doaj.org/article/228752836909455e95fb6dcce68176e6
Autor:
Amanbek Yerlan, Du Zhibin, Erlangga Yogi, da Fonseca Carlos M., Kurmanbek Bakytzhan, Pereira António
Publikováno v:
Open Mathematics, Vol 18, Iss 1, Pp 1227-1229 (2020)
In this short note, we provide a brief proof for a recent determinantal formula involving a particular family of banded matrices.
Externí odkaz:
https://doaj.org/article/feb7eb4e3577492f8fe519924a72adf2
We consider the problem of the reconstruction of a Schwarz matrix from exactly one given eigenvalue. This inverse eigenvalue problem leads to the Jacobi orthogonal polynomials~$\{P_k^{(-n,n)}\}_{k=0}^{n-1}$ that can be treated as a discrete finite an
Externí odkaz:
http://arxiv.org/abs/2406.11032
We explicitly construct families of simple modules for Lie algebras of rank $2$, on which certain commutative subalgebra acts diagonally and has a simple spectrum. In type $A$ these modules are well known generic Gelfand-Tsetlin modules and they can
Externí odkaz:
http://arxiv.org/abs/2402.00483
Autor:
Du Zhibin, da Fonseca Carlos M.
Publikováno v:
Open Mathematics, Vol 14, Iss 1, Pp 832-840 (2016)
In this work we show that the Bruhat rank of a symmetric (0,1)-matrix of order n with a staircase pattern, total support, and containing In, is at most 2. Several other related questions are also discussed. Some illustrative examples are presented.
Externí odkaz:
https://doaj.org/article/b2440b51479343c89f0b24797bcd811c
Autor:
Du, Zhibin, da Fonseca, Carlos M.
Publikováno v:
Applicable Analysis and Discrete Mathematics, 2022 Oct 01. 16(2), 485-494.
Externí odkaz:
https://www.jstor.org/stable/27174769