Results 91 to 100 of about 10,299 (219)

Stable Cuts, NAC‐Colourings and Flexible Realisations of Graphs

Journal 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, Dániel Garamvölgyi, John Haslegrave, Tony Huynh, Jan Legerský, Anthony Nixon   +5 more
wiley   +1 more source

One-Three Join: A Graph Operation and Its Consequences

Discussiones Mathematicae Graph Theory, 2017
In this paper, we introduce a graph operation, namely one-three join. We show that the graph G admits a one-three join if and only if either G is one of the basic graphs (bipartite, complement of bipartite, split graph) or G admits a constrained ...
Shalu M.A., Devi Yamini S.
doaj   +1 more source

Linear Versus Centred Colouring via Pseudogrids

Journal 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, Vida Dujmović, Hussein Houdrouge, Mehrnoosh Javarsineh, Pat Morin   +4 more
wiley   +1 more source

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

Journal 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

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

Journal 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

Nearly bipartite graphs

Discrete Mathematics, 2003
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Ervin Györi, Vladimir Nikiforov 0001, Richard H. Schelp   +2 more
openaire   +2 more sources

On Fork‐Free t‐Perfect Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT In an effort to understand the complexity of the maximum independent set problem, Chvátal introduced t‐perfect graphs. While a full characterization of this class remains open, important progress has been made for claw‐free graphs [Bruhn and Stein, Math. Program. 2012] and P 5 ${P}_{5}$‐free graphs [Bruhn and Fuchs, SIAM J. Discrete Math. 2017]
Yixin Cao, Shenghua Wang
wiley   +1 more source

Multi-view Clustering Based on Bipartite Graph Cross-view Graph Diffusion [PDF]

Jisuanji kexue
Multi-view clustering is an research hotspots in the field of unsupervised learning.Recently,the method based on cross-view graph diffusion uses the complementary information between multiple views to obtain a unified graph for clustering on the basis of
WANG Jinfu, WANG Siwei, LIANG Weixuan, YU Shengju, ZHU En
doaj   +1 more source

Tree Independence Number III. Thetas, Prisms and Stars

Journal of Graph Theory, EarlyView.
ABSTRACT We prove that for every t ∈ N $t\in {\mathbb{N}}$ there exists τ = τ ( t ) ∈ N $\tau =\tau (t)\in {\mathbb{N}}$ such that every (theta, prism, K 1 , t ${K}_{1,t}$)‐free graph has tree independence number at most τ $\tau $ (where we allow “prisms” to have one path of length zero).
Maria Chudnovsky, Sepehr Hajebi, Nicolas Trotignon   +2 more
wiley   +1 more source

Allocation of Indivisible Items With a Common Preference Graph: Minimizing Total Dissatisfaction

Networks, EarlyView.
ABSTRACT Allocating indivisible items among a set of agents is a frequently studied discrete optimization problem. In the setting considered in this work, the agents' preferences over the items are assumed to be identical. We consider a very recent measure for the overall quality of an allocation which does not rely on numerical valuations of the items.
Nina Chiarelli, Clément Dallard, Andreas Darmann, Stefan Lendl, Martin Milanič, Peter Muršič, Ulrich Pferschy   +6 more
wiley   +1 more source