A matrix characterization for the D-v-semiclassical and D-v-coherent orthogonal polynomials

We present a new structure relation for the sequence of orthogonal polynomials associated with a D-v-semiclassical linear functional of class s, and then we use it to obtain a matrix characterization of the D-v-semiclassical orthogonal polynomials in terms of the Jacobi matrix associated with the multiplication operator in the basis of orthonormal polynomials, and the nonsingular lower triangular matrix that represents the orthogonal polynomials with respect to some bases of polynomials. We also provide a matrix characterization of D-v-coherent pairs of linear functionals.The work of the first author was supported by a grant of the Secretar´ıa de Educaci´on P´ublica of M´exico and the Mexican Government. The work of the second author was supported by Consejo Nacional de Ciencia y Tecnolog´ıa of M´exico, grant 156668. The work of the third author was supported by Direcci ´on General de Investigaci´on Cient´ıfica y T´ecnica, Ministerio de Econom´ıa y Competitividad of Spain, grant MTM2012-36732-C03-01. The authors thank the anonymous referee for her/his valuable comments and suggestions. They contributed to improve the presentation of the manuscript