Results 141 to 150 of about 1,017,247 (314)

Decompositions of regular bipartite graphs [PDF]

open access: yes, 1991
In this paper we discuss isomorphic decompositions of regular bipartite graphs into trees and forests. We prove that: (1) there is a wide class of r-regular bipartite graphs that are decomposable into any tree of size r, (2) every r-regular bipartite ...
Truszczyński, Miroslaw   +2 more
core   +1 more source

Stable Cuts, NAC‐Colourings and Flexible Realisations of Graphs

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT A (2‐dimensional) realisation of a graph G $G$ is a pair ( G , p ) $(G,p)$, where p $p$ maps the vertices of G $G$ to R 2 ${{\mathbb{R}}}^{2}$. A realisation is flexible if it can be continuously deformed while keeping the edge lengths fixed, and rigid otherwise.
Katie Clinch   +5 more
wiley   +1 more source

Dominating bipartite subgraphs in graphs [PDF]

open access: yes, 2005
A graph G is hereditarily dominated by a class of connected graphs if each connected induced subgraph of G contains a dominating induced subgraph belonging to . In this paper we characterize graphs hereditarily dominated by classes of complete bipartite
Tuza, Zsolt   +2 more
core   +1 more source

Linear Versus Centred Colouring via Pseudogrids

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT A centred colouring of a graph is a vertex colouring in which every connected subgraph contains a vertex whose colour is unique and a linear colouring is a vertex colouring in which every (not‐necessarily induced) path contains a vertex whose colour is unique. For a graph G $G$, the centred chromatic number χ cen ( G ) ${\chi }_{\text{cen}}(G)$
Prosenjit Bose   +4 more
wiley   +1 more source

Some applications of matching theorems [PDF]

open access: yes, 2010
PhDThis thesis contains the results of two investigations. The rst concerns the 1- factorizability of regular graphs of high degree. Chetwynd and Hilton proved in 1989 that all regular graphs of order 2n and degree 2n where > 1 2 ( p 7 1) 0 ...
Vaughan, Emil Richard
core  

Bipartite almost distance-hereditary graphs [PDF]

open access: yes, 2008
The notion of distance-heredity in graphs has been extended to construct the class of almost distance-hereditary graphs (an increase of the distance by one unit is allowed by induced subgraphs).
Aïder, Méziane
core   +1 more source

A Min–Max Relation on Dicuts and Dijoins in Weighted Chordal Digraphs

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT In a digraph, a dicut is a cut where all the arcs cross in one direction. A dijoin is a subset of arcs that intersects every dicut. Edmonds and Giles conjectured that in a weighted digraph, the minimum weight of a dicut is equal to the maximum size of a packing of dijoins. This has been disproved. However, the unweighted version conjectured by
Gérard Cornuéjols, Siyue Liu, R. Ravi
wiley   +1 more source

Absolute retracts of bipartite graphs [PDF]

open access: yes, 1987
A bipartite graph G is an absolute retract if every isometric embedding g of G into a bipartite graph H is a coretraction (that is, there exists an edge-preserving map h from H to G such that hg is the identity map on G).
Schütte, H, Dählmann, A, Bandelt, H.J
core   +1 more source

Density Conditions for k $k$ Vertex‐Disjoint Triangles in Tripartite Graphs

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT Let n , k $n,k$ be positive integers such that n ≥ k $n\ge k$ and G $G$ be a tripartite graph with parts A , B , C $A,B,C$ such that ∣ A ∣ = ∣ B ∣ = ∣ C ∣ = n $| A| =| B| =| C| =n$. Denote the edge densities of G [ A , B ] , G [ A , C ] $G[A,B],G[A,C]$ and G [ B , C ] $G[B,C]$ by α , β $\alpha ,\beta $ and γ $\gamma $, respectively.
Mingyang Guo, Klas Markström
wiley   +1 more source

2-biplacement without fixed points of (p,q)-bipartite graphs [PDF]

open access: yesOpuscula Mathematica, 2005
In this paper we consider \(2\)-biplacement without fixed points of paths and \((p,q)\)-bipartite graphs of small size. We give all \((p,q)\)-bipartite graphs \(G\) of size \(q\) for which the set \(\mathcal{S}^{*}(G)\) of all \(2\)-biplacements of \(G\)
Beata Orchel
doaj  

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