Faces of faces of the tridiagonal Birkhoff polytope
| Autor: | Enide Andrade Martins, Liliana N. Costa |
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| Rok vydání: | 2010 |
| Předmět: |
Discrete mathematics
Doubly stochastic matrix Numerical Analysis Algebra and Number Theory Quadrilateral Birkhoff polytope Tridiagonal matrix Number of faces Polytope Square matrix Enumerative combinatorics Combinatorics Polyhedron Mathematics::Metric Geometry Discrete Mathematics and Combinatorics Geometry and Topology Number of vertices Number of edges Tridiagonal Birkhoff polytope Algorithms Mathematics |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| ISSN: | 0024-3795 |
| DOI: | 10.1016/j.laa.2009.10.030 |
| Popis: | The tridiagonal Birkhoff polytope, Ω n t , is the set of real square matrices with nonnegative entries and all rows and columns sums equal to 1 that are tridiagonal. This polytope arises in many problems of enumerative combinatorics, statistics, combinatorial optimization, etc. In this paper, for a given a p -face of Ω n t , we determine the number of faces of lower dimension that are contained in it and we discuss its nature. In fact, a 2-face of Ω n t is a triangle or a quadrilateral and the cells can only be tetrahedrons, pentahedrons or hexahedrons. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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