Results 61 to 70 of about 9,740 (155)

Rainbow connection and forbidden subgraphs

open access: yesDiscrete Mathematics, 2015
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Premysl Holub   +3 more
openaire   +1 more source

Decomposition of 4k-regular graphs into k 4-regular K5-free and (K5−e)-free subgraphs [PDF]

open access: yesDiscrete Mathematics Letters, 2021
Rachel Johnson   +4 more
doaj   +1 more source

Characterizing the forbidden pairs for graphs to be super-edge-connected

open access: yesAKCE International Journal of Graphs and Combinatorics
Let [Formula: see text] be a set of given connected graphs. A graph G is said to be [Formula: see text]-free if G contains no H as an induced subgraph for any [Formula: see text].
Hazhe Ye, Yingzhi Tian
doaj   +1 more source

On Oriented Colourings of Graphs on Surfaces

open access: yesJournal of Graph Theory, Volume 112, Issue 4, Page 357-369, August 2026.
ABSTRACT For an oriented graph G, the least number of colours required to oriented colour G is called the oriented chromatic number of G and denoted χ o ( G ). For a non‐negative integer g let χ o ( g ) be the least integer such that χ o ( G ) ≤ χ o ( g ) for every oriented graph G with Euler genus at most g.
Alexander Clow
wiley   +1 more source

Stability for large forbidden subgraphs [PDF]

open access: yesJournal of Graph Theory, 2009
AbstractIn this note we strengthen the stability theorem of Erdős and Simonovits. Write Kr(s1, …, sr) for the complete r‐partite graph with classes of sizes s1, …, sr and Tr(n) for the r‐partite Turán graph of order n. Our main result is:For all r≥2 and all sufficiently small c>0, ε>0, every graph G of sufficiently large order n with e(G)>(1−1/
openaire   +2 more sources

Small clique number graphs with three trivial critical ideals [PDF]

open access: yes, 2013
The critical ideals of a graph are the determinantal ideals of the generalized Laplacian matrix associated to a graph. In this article we provide a set of minimal forbidden graphs for the set of graphs with at most three trivial critical ideals.
Carlos, Carlos A. Alfaro, E. Valencia
core  

Unit Interval Editing is Fixed-Parameter Tractable

open access: yes, 2016
Given a graph~$G$ and integers $k_1$, $k_2$, and~$k_3$, the unit interval editing problem asks whether $G$ can be transformed into a unit interval graph by at most $k_1$ vertex deletions, $k_2$ edge deletions, and $k_3$ edge additions.
D Marx   +12 more
core   +1 more source

Edge‐Length Preserving Embeddings of Graphs Between Normed Spaces

open access: yesJournal of Graph Theory, Volume 112, Issue 4, Page 491-506, August 2026.
ABSTRACT The concept of graph embeddability, initially formalized by Belk and Connelly and later expanded by Sitharam and Willoughby, extends the question of embedding finite metric spaces into a given normed space. A finite simple graph G = ( V , E ) is said to be ( X , Y )‐embeddable if any set of induced edge lengths from an embedding of G into a ...
Sean Dewar   +3 more
wiley   +1 more source

Degree Powers in Graphs with Forbidden Subgraphs [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2004
For every real $p>0$ and simple graph $G,$ set $$ f\left( p,G\right) =\sum_{u\in V\left( G\right) }d^{p}\left( u\right) , $$ and let $\phi\left( r,p,n\right) $ be the maximum of $f\left( p,G\right) $ taken over all $K_{r+1}$-free graphs $G$ of order $n.$ We prove that, if $0 < p < r,$ then$$ \phi\left( r,p,n\right) =f\left( p,T_{r ...
Béla Bollobás, Vladimir Nikiforov 0001
openaire   +3 more sources

Graphs whose Laplacian eigenvalues are almost all 1 or 2

open access: yesSpecial Matrices
We explicitly determine all connected graphs whose Laplacian matrices have at most four eigenvalues different from 1 and 2.
Mohammadian Ali, Xu Shanshan
doaj   +1 more source

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