Results 11 to 20 of about 106 (86)
Discussiones Mathematicae Graph Theory, 2017 We characterize the class L32$L_3^2 $ of intersection graphs of hypergraphs with rank at most 3 and multiplicity at most 2 by means of a finite list of forbidden induced subgraphs in the class of threshold graphs.
Metelsky Yury +2 more
doaj +2 more sources
Even circuits in oriented matroids [PDF]
, 2022 In this paper we generalise the even directed cycle problem, which asks whether a given digraph contains a directed cycle of even length, to orientations of regular matroids.
Heuer, Karl +2 more
core +1 more source
On Accurate Domination in Graphs
Discussiones Mathematicae Graph Theory, 2019 A dominating set of a graph G is a subset D ⊆ VG such that every vertex not in D is adjacent to at least one vertex in D. The cardinality of a smallest dominating set of G, denoted by γ(G), is the domination number of G. The accurate domination number of
Cyman Joanna +2 more
doaj +1 more source
International Journal of Mathematical Combinatorics, Vol.5 [PDF]
, 2011 The International J.Mathematical Combinatorics (ISSN 1937-1055) is a fully refereed international journal, sponsored by the MADIS of Chinese Academy of Sciences and published in USA quarterly comprising 460 pages approx.
Mao, Linfan (Editor-in-Chief)
core +2 more sources
Minimally Strong Subgraph (k,ℓ)-Arc-Connected Digraphs
Discussiones Mathematicae Graph Theory, 2022 Let D = (V,A) be a digraph of order n, S a subset of V of size k and 2 ≤ k ≤ n. A subdigraph H of D is called an S-strong subgraph if H is strong and S ⊆ V (H). Two S-strong subgraphs D1 and D2 are said to be arc-disjoint if A(D1) ∩ A(D2) = ∅.
Sun Yuefang, Jin Zemin
doaj +1 more source
On the edge set of graphs of lattice paths
International Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 61, Page 3291-3299, 2004., 2004 This note explores a new family of graphs defined on the set of paths of the m × n lattice. We let each of the paths of the lattice be represented by a vertex, and connect two vertices by an edge if the corresponding paths share more than k steps, where k is a fixed parameter 0 = k = m + n. Each such graph is denoted by G(m, n, k).
Steven Klee, Lara Pudwell, Rick Gillman
wiley +1 more source
Old and new generalizations of line graphs
International Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 29, Page 1509-1521, 2004., 2004 Line graphs have been studied for over seventy years. In 1932, H. Whitney showed that for connected graphs, edge‐isomorphism implies isomorphism except for K3 and K1,3. The line graph transformation is one of the most widely studied of all graph transformations.
Jay Bagga
wiley +1 more source
Existence of Regular Nut Graphs for Degree at Most 11
Discussiones Mathematicae Graph Theory, 2020 A nut graph is a singular graph with one-dimensional kernel and corresponding eigenvector with no zero elements. The problem of determining the orders n for which d-regular nut graphs exist was recently posed by Gauci, Pisanski and Sciriha.
Fowler Patrick W. +4 more
doaj +1 more source
Characterizing symmetric diametrical graphs of order 12 and diameter 4
International Journal of Mathematics and Mathematical Sciences, Volume 30, Issue 3, Page 145-149, 2002., 2002 A diametrical graph G is said to be symmetric if d(u,v)+d(v,u¯)=d(G) for all u, v ∈ V(G), where u¯ is the buddy of u. If moreover, G is bipartite, then it is called an S‐graph. It would be shown that the Cartesian product K2 × C6 is not only the unique S‐graph of order 12 and diameter 4, but also the unique symmetric diametrical graph of order 12 and ...
S. Al-Addasi, H. Al-Ezeh
wiley +1 more source
Characterizing Atoms that Result from Decomposition by Clique Separators
Discussiones Mathematicae Graph Theory, 2017 A graph is defined to be an atom if no minimal vertex separator induces a complete subgraph; thus, atoms are the graphs that are immune to clique separator decomposition.
McKee Terry A.
doaj +1 more source