Abstract
We deal with the 2‐orthogonal, 2‐symmetric self‐associated sequence (2‐orthogonal Tchebychev polynomials) and its cubic components. We prove that all the forms (linear functionals) arising are third degree forms. Therefore, an introduction to third degree forms is provided. We look for the connection between these components which are 2‐orthogonal with respect to the functional vector t(w0{μ},w1 μ) and orthogonal sequences with respect to w0 μ, μ=0,1,2. Associated forms w0 μ)1) and their inverse w0 μ)-1 are also studied through the symmetrized w0}0 μ, μ=0,1,2. Further, we give integral representations for some of these forms.
Similar content being viewed by others
References
J. Alaya and P. Maroni, Symmetric Laguerre-Hahn forms of class s = 1, Int. Transf. and Spc. Funct. 4(4) (1996) 301–320.
A.I. Aptekarev, Multiple orthogonal polynomials, J. Comput. Appl. Math. 99 (1998) 423–447.
A. Aptekarev, V. Kaliaguine and J. Van Iseghem, Genetic sum's representation for the moments of system of Stieltjes functions and its application, Publ. ANO 386, Univ. Sci. Tech. de Lille (1998). Constr. Approx., submitted.
M.G. de Bruin, Simultaneous Pad´e approximants and orthogonality, in: Lecture Notes in Mathematics, Vol. 1171 (Springer, Berlin, 1984) pp. 74–83.
T.S. Chihara, An Introduction to Orthogonal Polynomials (Gordon and Breach, New York, 1978).
K. Douak and P. Maroni, Les polyn^omes orthogonaux "classiques" de dimension deux, Analysis 12 (1992) 71–107.
K. Douak and P. Maroni, On d-orthogonal Tchebychev polynomials, I, Appl. Num. Math. 24 (1997) 23–53.
P. Duren, Theory of Hp Spaces (Academic Press, New York, 1970).
A. Kurosh, Cours d'Alg`ebre Sup´erieure (Mir, Moscow, 1971).
K. Mahler, Perfect systems, Compositio Math. 19 (1968) 95–166.
P. Maroni, Le calcul des formes lin´eaires et les polyn^omes orthogonaux semi-classiques, in: Lecture Notes in Mathematics, Vol. 1329 (1988) pp. 279–290.
P. Maroni, L'orthogonalit´e et les r´ecurrences de polyn^omes d'ordre sup´erieur `a deux, Ann. Fac. Sci. Toulouse 10 (1989) 105–139.
P. Maroni, Sur la d´ecomposition quadratique d'une suite de polyn^omes orthogonaux, I, Rivista di Mat. Pura ed Appl. 6 (1990) 19–53.
P. Maroni, Une th´eorie alg´ebrique des polyn^omes orthogonaux. Application aux polyn^omes orthogonaux semi-classiques, Ann. Comput. Appl. Math. 9 (1991) 95–130.
P. Maroni, Two-dimensional orthogonal polynomials, their associated sets and the co-recursive sets, Numer. Algorithms 3 (1992) 299–312.
P. Maroni, An introduction to second degree forms, Adv. Comput. Math. 3 (1995) 59–88.
P. Maroni, On a regular form defined by a pseudo-function, Numer. Algorithms 11 (1996) 243–254.
P. Maroni, Semi-classical character and finite-type relations between polynomial sequences, Appl. Numer. Math. 31 (1999) 295–330.
Z. da Rocha, Shohat-Favard and Chebyshev's methods in d-orthogonality, Numer. Algorithms 20 (1999) 139–164.
V.N. Sorokin and J. Van Iseghem, Algebraic aspects of matrix orthogonality for vector polynomials, J. Approx. Theory 90 (1997) 97–116.
J. Van Iseghem, Approximants de Pad´e vectoriels, Th`ese d'Etat, Univ. des Sci. Tech. de Lille-Flandre-Artois (1987).
J. Van Iseghem, Vector orthogonal relations, vector QD-algorithm, J. Comput. Appl. Math. 19 (1987) 141–150.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ben Salah, I., Maroni, P. The connection between self‐associated two‐dimensional vector functionals and third degree forms. Advances in Computational Mathematics 13, 51–77 (2000). https://doi.org/10.1023/A:1018941924408
Issue Date:
DOI: https://doi.org/10.1023/A:1018941924408