d-Orthogonal polynomials;
d-Dimensional vectors of linear forms;
Recurrence relations;
Linear combinations of d-orthogonal polynomials;
Chebyshev d-orthogonal polynomials;
Associated and co-recursive d-orthogonal polynomials;
SEMICLASSICAL CHARACTER;
INVERSE PROBLEM;
SEQUENCES;
D O I:
10.1007/s40840-017-0589-2
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
The regularity of a linear combination of r consecutive elements of a monic d-orthogonal polynomial sequence has been studied when (r-1) is a multiple of d. This problem can be solved without the introduction of the concept of d-quasi-orthogonality. In the present contribution, we deal with the problem of d-orthogonality of a linear combination of two elements of a monic d-orthogonal polynomial sequence. This problem is also equivalent to the study the regularity of the left product of a linear form by a matrix polynomial of degree one.