Results 1 to 10 of about 331 (182)

Upward-closed hereditary families in the dominance order [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2022
The majorization relation orders the degree sequences of simple graphs into posets called dominance orders. As shown by Ruch and Gutman (1979) and Merris (2002), the degree sequences of threshold and split graphs form upward-closed sets within the ...
Michael D. Barrus, Jean A. Guillaume
doaj   +1 more source

Classes of graphs with restricted interval models [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 1999
We introduce q-proper interval graphs as interval graphs with interval models in which no interval is properly contained in more than q other intervals, and also provide a forbidden induced subgraph characterization of this class of graphs. We initiate a
Andrzej Proskurowski, Jan Arne Telle
doaj   +3 more sources

Hereditary Equality of Domination and Exponential Domination in Subcubic Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
Let γ(G) and γe(G) denote the domination number and exponential domination number of graph G, respectively. Henning et al., in [Hereditary equality of domination and exponential domination, Discuss. Math. Graph Theory 38 (2018) 275–285] gave a conjecture:
Chen Xue-Gang, Wang Yu-Feng, Wu Xiao-Fei
doaj   +1 more source

On the chromatic number of (P_{5},windmill)-free graphs [PDF]

open access: yesOpuscula Mathematica, 2017
In this paper we study the chromatic number of \((P_5, windmill)\)-free graphs. For integers \(r,p\geq 2\) the windmill graph \(W_{r+1}^p=K_1 \vee pK_r\) is the graph obtained by joining a single vertex (the center) to the vertices of \(p\) disjoint ...
Ingo Schiermeyer
doaj   +1 more source

Weakly threshold graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2018
We define a weakly threshold sequence to be a degree sequence $d=(d_1,\dots,d_n)$ of a graph having the property that $\sum_{i \leq k} d_i \geq k(k-1)+\sum_{i > k} \min\{k,d_i\} - 1$ for all positive $k \leq \max\{i:d_i \geq i-1\}$.
Michael D. Barrus
doaj   +1 more source

A Quasi-Hole Detection Algorithm for Recognizing k-Distance-Hereditary Graphs, with k < 2

open access: yesAlgorithms, 2021
Cicerone and Di Stefano defined and studied the class of k-distance-hereditary graphs, i.e., graphs where the distance in each connected induced subgraph is at most k times the distance in the whole graph. The defined graphs represent a generalization of
Serafino Cicerone
doaj   +1 more source

The graph grabbing game on {0,1}-weighted graphs

open access: yesResults in Applied Mathematics, 2019
The graph grabbing game is a two-player game on a weighted connected graph in which two players, Alice and Bob, alternatively remove non-cut vertices one by one to gain the weights on them.
Soogang Eoh, Jihoon Choi
doaj   +1 more source

Forbidden subgraph pairs for traceability of block-chains

open access: yesElectronic Journal of Graph Theory and Applications, 2013
A block-chain is a graph whose block graph is a path, i.e. it is either a $P_1$, a $P_2$, or a 2-connected graph, or a graph of connectivity 1 with exactly two end-blocks. A graph is called traceable if it contains a Hamilton path.
Binlong Li   +2 more
doaj   +1 more source

Characterising and recognising game-perfect graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2019
Consider a vertex colouring game played on a simple graph with $k$ permissible colours. Two players, a maker and a breaker, take turns to colour an uncoloured vertex such that adjacent vertices receive different colours.
Dominique Andres, Edwin Lock
doaj   +1 more source

Characterizing Forbidden Pairs for the Edge-Connectivity of a Connected Graph to Be Its Minimum Degree

open access: yesAxioms, 2022
Let H be a class of given graphs. A graph G is said to be H-free if G contains no induced copies of H for any H∈H. In this article, we characterize all connected subgraph pairs {R,S} guranteeing the edge-connectivity of a connected {R,S}-free graph to ...
Junfeng Du, Ziwen Huang, Liming Xiong
doaj   +1 more source

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