Explicit inverse of a tridiagonal k-Toeplitz matrix

• Autor(a) principal: Fonseca, C. M. da
• Data de Publicação: 2005
• Outros Autores: Petronilho, J.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/7740; https://doi.org/10.1007/s00211-005-0596-3

Summary We obtain explicit formulas for the entries of the inverse of a nonsingular and irreducible tridiagonal k-Toeplitz matrix A. The proof is based on results from the theory of orthogonal polynomials and it is shown that the entries of the inverse of such a matrix are given in terms of Chebyshev polynomials of the second kind. We also compute the characteristic polynomial of A which enables us to state some conditions for the existence of A-1. Our results also extend known results for the case when the residue mod k of the order of A is equal to 0 or k-1 (Numer. Math., 10 (1967), pp. 153–161.).