Des algorithmes linéaires pour les problèmes de partition, de recouvrement et de couplage dans les hypergraphes d'intervalles
Descendants and ascendants in binary trees.
Descendants in heap ordered trees or a triumph of computer algebra.
Descendants in increasing trees.
Descents in noncrossing trees.
Description combinatoire des ultramétriques
Descriptions of state spaces of orthomodular lattices (the hypergraph approach)
Using the general hypergraph technique developed in [7], we first give a much simpler proof of Shultz's theorem [10]: Each compact convex set is affinely homeomorphic to the state space of an orthomodular lattice. We also present partial solutions to open questions formulated in [10] - we show that not every compact convex set has to be a state space of a unital orthomodular lattice and that for unital orthomodular lattices the state space characterization can be obtained in the context of unital...
Destroying symmetry by orienting edges: complete graphs and complete bigraphs
Our purpose is to introduce the concept of determining the smallest number of edges of a graph which can be oriented so that the resulting mixed graph has the trivial automorphism group. We find that this number for complete graphs is related to the number of identity oriented trees. For complete bipartite graphs , s ≤ t, this number does not always exist. We determine for s ≤ 4 the values of t for which this number does exist.
Determinantal generating functions of colored spanning forests.
Déterminants et intégrales de Fresnel
On présente ici une approche directe et géométrique pour le calcul des déterminants d’opérateurs de type Schrödinger sur un graphe fini. Du calcul de l’intégrale de Fresnel associée, on déduit le déterminant. Le calcul des intégrales de Fresnel est grandement facilité par l’utilisation simultanée du théorème de Fubini et d’une version linéaire du calcul symbolique des opérateurs intégraux de Fourier. On obtient de façon directe une formule générale exprimant le déterminant en terme des conditions...
Determination of all rigid groups of order not exceeding 60
Determination of Large Families and Diameter of Equiseparable Trees
Determining the maximal degree of a tree given by its distance matrix
Detour chromatic numbers
The nth detour chromatic number, χₙ(G) of a graph G is the minimum number of colours required to colour the vertices of G such that no path with more than n vertices is monocoloured. The number of vertices in a longest path of G is denoted by τ( G). We conjecture that χₙ(G) ≤ ⎡(τ(G))/n⎤ for every graph G and every n ≥ 1 and we prove results that support the conjecture. We also present some sufficient conditions for a graph to have nth chromatic number at most 2.
Diagonal similarity of matrices
Diagonalizable embedding of composition graphs
Diameter in path graphs.
Diameter in walk graphs.
Diameter-invariant graphs
The diameter of a graph is the maximal distance between two vertices of . A graph is said to be diameter-edge-invariant, if for all its edges, diameter-vertex-invariant, if for all its vertices and diameter-adding-invariant if for all edges of the complement of the edge set of . This paper describes some properties of such graphs and gives several existence results and bounds for parameters of diameter-invariant graphs.
Diametrically critical tournaments