2005/04/01 by T. Constantinescu, Constantinescu, T., Nermine El-Sissi +1
Mathematics · #Advanced Combinatorial Mathematics #Combinatorics (math.CO) #FOS: Mathematics #Functional Analysis (math.FA) #Mathematical functions and polynomials #Mathematics and Applications #math.CO #math.FA
paper · pdf · doi:10.48550/arxiv.math/0504029
12 pages, 7 figures
arxiv created 2005/04/01 · openalex publication_date 2005/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We discuss the structure of positive definite kernels in terms of operator models. In particular, we introduce two models, one of Hessenberg type and another one that we call near triangular. These models produce parametrizations of the kernels and we describe the combinatorial nature of these parametrizations in terms of lattice paths of Dyck and Lukasiewicz type.