Results 11 to 20 of about 6,109 (206)

On bipartite‐mixed graphs [PDF]

open access: yesJournal of Graph Theory, 2018
AbstractMixed graphs can be seen as digraphs that have both arcs and edges (or digons, that is, two opposite arcs). In this article, we consider the case where such graphs are bipartite. As main results, we show that in this context the Moore‐like bound is attained in the case of diameter , and that bipartite‐mixed graphs of diameter do not exist.
Dalfó Simó, Cristina   +2 more
openaire   +5 more sources

Decycling bipartite graphs

open access: yesJournal of Graph Algorithms and Applications, 2021
Let $G=(V,E)$ be a graph and let $S\subseteq V$ be a subset of its vertices. If the subgraph of $G$ induced by $V\setminus S$ is acyclic, then $S$ is said to be a decycling set of $G$. The size of a smallest decycling set of $G$ is called the decycling number of $G$. Determining the decycling number of a graph $G$ is NP-hard, even if $G$ is bipartite.
openaire   +3 more sources

Size Ramsey number of bipartite graphs and bipartite Ramanujan graphs [PDF]

open access: yesTransactions on Combinatorics, 2019
Given a graph $ G $, a graph $ F $ is said to be Ramsey for $ G $ if in every edge coloring of $F$ with two colors, there exists a monochromatic copy of $G$. The minimum number of edges of a graph $ F $ which is Ramsey for $ G $ is called the size-Ramsey
Ramin Javadi, Farideh Khoeini
doaj   +1 more source

Cyclability in bipartite graphs [PDF]

open access: yesOpuscula Mathematica, 2009
Let \(G=(X,Y,E)\) be a balanced \(2\)-connected bipartite graph and \(S \subset V(G)\). We will say that \(S\) is cyclable in \(G\) if all vertices of \(S\) belong to a common cycle in \(G\).
Denise Amar   +2 more
doaj   +1 more source

Koszul Bipartite Graphs

open access: yesAdvances in Applied Mathematics, 1999
Let \(R = K[t_1, \ldots , t_d]\) be the polynomial ring in \(d\) indeterminates over a field \(K\). If \(G\) is a bipartite graph on the vertex set \(\{ 1, \ldots , d \}\), define \(K[G]\) to be the subalgebra of \(R\) generated by all monomials \(t_i t_j\) such that \(\{ i,j \}\) is an edge of \(G\). It is shown that if every \(n\)-cycle \((n \geq 6)\)
Ohsugi, Hidefumi, Hibi, Takayuki
openaire   +2 more sources

Bipartite Domination in Graphs

open access: yesMathematica Pannonica, 2022
The bipartite domination number of a graph is the minimum size of a dominating set that induces a bipartite subgraph. In this paper we initiate the study of this parameter, especially bounds involving the order, the ordinary domination number, and the chromatic number.
Bachstein, Anna   +2 more
openaire   +2 more sources

Cellular Bipartite Graphs

open access: yesEuropean Journal of Combinatorics, 1996
Graphs that are obtained from single edges and even cycles by successive amalgamations are called cellular graphs. Especially cellular bipartite graphs are investigated in this paper. Since graphs with their shortest-path metrics are particular instances of finite metric spaces, these investigations are done from a metric point of view.
Bandelt, Hans-Jürgen, Chepoi, Victor
openaire   +1 more source

New class of integral bipartite graphs with large diameter [PDF]

open access: yesTransactions on Combinatorics, 2018
In this paper‎, ‎we construct a new class of integral bipartite graphs (not necessarily trees) with large even diameters‎. ‎In fact‎, ‎for every finite set $A$ of positive integers of size $k$ we construct an integral bipartite graph $G$ of diameter $2k$
Alireza Fiuj Laali   +1 more
doaj   +1 more source

On bipartite divisor graph for character degrees [PDF]

open access: yesInternational Journal of Group Theory, 2017
‎‎The concept of the bipartite divisor graph for integer subsets has been considered in [M‎. ‎A‎. ‎Iranmanesh and C‎. ‎E‎. ‎Praeger‎, ‎Bipartite divisor graphs for integer subsets‎, Graphs Combin.‎,  26 (2010) 95--105.]‎.
Seyed Ali Moosavi
doaj   +1 more source

Embedding into Bipartite Graphs [PDF]

open access: yesSIAM Journal on Discrete Mathematics, 2010
16 pages, 2 ...
Böttcher, Julia   +2 more
openaire   +2 more sources

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