Results 131 to 140 of about 2,876,957 (249)
Bipartite Digraphs with Modular Concept Lattices of height 2
Қарағанды университетінің хабаршысы. Математика сериясыThis paper investigates the interaction between Formal Concept Analysis (FCA) and graph theory, with a focus on understanding the structure and representation of concept lattices derived from bipartite directed graphs.
A.O. Basheyeva +2 more
doaj +1 more source
Journal of Graph Theory, Volume 113, Issue 4, Page 553-570, December 2026.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‐free graphs [Bruhn and Fuchs, SIAM J. Discrete Math. 2017]. We take
Yixin Cao, Shenghua Wang
wiley +1 more source
Tree Independence Number III. Thetas, Prisms and Stars
Journal of Graph Theory, Volume 113, Issue 4, Page 619-633, December 2026.ABSTRACT We prove that for every t ∈ N there exists τ = τ ( t ) ∈ N such that every (theta, prism, K 1 , t)‐free graph has tree independence number at most τ (where we allow “prisms” to have one path of length zero).
Maria Chudnovsky +2 more
wiley +1 more source
S-REGULAR CUBIC GRAPHS AS COVERINGS OF THE COMPLETE BIPARTITE GRAPH K-3,K-3
, 2019 A graph is s-regular if its automorphism group acts freely and transitively on the set of s-arcs. An infinite family of cubic 1-regular graphs was constructed in [10], as cyclic coverings of the three-dimensional Hypercube. In this paper, we classify the
Kwak, JH, Feng, YQ
core +1 more source
P2p-factorization of a complete bipartite graph
Discrete Mathematics, 1993 Given a graph \(G\), every spanning subgraph with all its components isomorphic to the \(2k\)-vertex path is called a \(P_{2k}\)-factor of \(G\), for a fixed integer \(k\geq 1\). It is shown that the complete bipartite graph \(K_{n,m}\) is the edge-disjoint union of \(P_{2k}\)-factors if and only if \(m=n\) and \(m\equiv 0\mod{k(2k-1)}\).
openaire +2 more sources
Stable Cuts, NAC‐Colourings and Flexible Realisations of Graphs
Journal of Graph Theory, Volume 113, Issue 3, Page 411-427, November 2026.ABSTRACT A (2‐dimensional) realisation of a graph G is a pair ( G , p ), where p maps the vertices of G to R 2. A realisation is flexible if it can be continuously deformed while keeping the edge lengths fixed, and rigid otherwise. We say that G is rigid if every generic realisation of G is rigid; otherwise, G is flexible. In this paper, we investigate
Katie Clinch +5 more
wiley +1 more source
Linear Versus Centred Colouring via Pseudogrids
Journal of Graph Theory, Volume 113, Issue 3, Page 448-461, November 2026.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.
Prosenjit Bose +4 more
wiley +1 more source
A Min–Max Relation on Dicuts and Dijoins in Weighted Chordal Digraphs
Journal of Graph Theory, Volume 113, Issue 3, Page 462-469, November 2026.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
Two Self‐Stabilizing Algorithms for the Maximal Pentagon Partitioning Problem
Concurrency and Computation: Practice and Experience, Volume 38, Issue 19, October 2026.ABSTRACT Given an undirected graph G=(V,E)$$ G=\left(V,E\right) $$, a collection of disjoint subsets of nodes π={V1,…,Vk}(V=V1∪⋯∪Vk)$$ \pi =\left\{{V}_1,\dots, {V}_k\right\}\kern0.3em \left(V={V}_1\cup \cdots \cup {V}_k\right) $$ is called a pentagon partition if each subset Vi(1≤i≤k)$$ {V}_i\kern0.3em \left(1\le i\le k\right) $$ satisfies one of the ...
Tota Yamada +2 more
wiley +1 more source
Ecology and Evolution, Volume 16, Issue 10, October 2026.We present the largest tropical tri‐trophic plant–gall–parasitoid network documented to date, assembled from lowland rainforest in Papua New Guinea. The network reveals strikingly high specialisation, in addition to gall traits such as apparency shaping parasitoid richness.
Philip T. Butterill +5 more
wiley +1 more source