Results 41 to 50 of about 3,632 (158)

Connected matchings in chordal bipartite graphs

Discrete Optimization, 2014
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Jobson, Adam S., Kézdy, André E., White, Susan C.   +2 more
openaire   +1 more source

Nearly Hamilton cycles in sublinear expanders and applications

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract We develop novel methods for constructing nearly Hamilton cycles in sublinear expanders with good regularity properties, as well as new techniques for finding such expanders in general graphs. These methods are of independent interest due to their potential for various applications to embedding problems in sparse graphs.
Shoham Letzter, Abhishek Methuku, Benny Sudakov   +2 more
wiley   +1 more source

Partitioning Perfect Graphs into Stars

, 2016
The partition of graphs into "nice" subgraphs is a central algorithmic problem with strong ties to matching theory. We study the partitioning of undirected graphs into same-size stars, a problem known to be NP-complete even for the case of stars on three
Bredereck, Robert, Bulteau, Laurent, Chen, Jiehua, Froese, Vincent, Niedermeier, Rolf, van Bevern, René, Woeginger, Gerhard J.   +6 more
core   +3 more sources

Chordal Graphs, Even‐Hole‐Free Graphs and Sparse Obstructions to Bounded Treewidth

Journal of Graph Theory, Volume 110, Issue 3, Page 351-365, November 2025.
ABSTRACT Even‐hole‐free graphs pose a central challenge in identifying hereditary classes of bounded treewidth. We investigate this matter by presenting and studying the following conjecture: for an integer t ≥ 4 and a graph H, every even‐hole‐free graph of large enough treewidth has an induced subgraph isomorphic to either K t or H, if (and only if) H
Sepehr Hajebi
wiley   +1 more source

Matchings, coverings, and Castelnuovo-Mumford regularity

, 2014
We show that the co-chordal cover number of a graph G gives an upper bound for the Castelnuovo-Mumford regularity of the associated edge ideal. Several known combinatorial upper bounds of regularity for edge ideals are then easy consequences of covering ...
Woodroofe, Russ
core   +1 more source

On a Variant of the Minimum Path Cover Problem in Acyclic Digraphs: Computational Complexity Results and Exact Method

Networks, Volume 86, Issue 3, Page 325-357, October 2025.
ABSTRACT The Minimum Path Cover (MPC) problem consists of finding a minimum‐cardinality set of node‐disjoint paths that cover all nodes in a given graph. We explore a variant of the MPC problem on directed acyclic graphs (DAGs) where, given a subset of arcs, each path within the MPC should contain at least one arc from this subset.
Nour ElHouda Tellache, Roberto Baldacci
wiley   +1 more source

Non-vanishing of Betti numbers of edge ideals and complete bipartite subgraphs [PDF]

, 2014
Given a finite simple graph one can associate the edge ideal. In this paper we prove that a graded Betti number of the edge ideal does not vanish if the original graph contains a set of complete bipartite subgraphs with some conditions.
Kimura, Kyouko
core  

Regularity of Edge Ideals and Their Powers

, 2018
We survey recent studies on the Castelnuovo-Mumford regularity of edge ideals of graphs and their powers. Our focus is on bounds and exact values of $\text{ reg } I(G)$ and the asymptotic linear function $\text{ reg } I(G)^q$, for $q \geq 1,$ in terms of
A Alilooee, A Alilooee, A Banerjee, A Banerjee, A Tuyl Van, AV Jayanthan, Christopher A. Francisco, E Nevo, E Nevo, F Khosh-Ahang, G Kalai, G Lyubeznik, G Wegner, H Dao, HT Hà, HT Hà, Huy Tài Hà, J Herzog, J Herzog, JA Eagon, K Cameron, K-N Lin, M Katzman, M Kummini, M Mahmoudi, M. Moghimian, NC Minh, Nursel Erey, NV Trung, O Fernàndez-Ramos, R Bouchat, R Woodroofe, R Woodroofe, Ralf Fröberg, S Beyarslan, S Morey, SD Cutkosky, T Biyikoglu, T Hibi, V Kodiyalam   +39 more
core   +1 more source

Opportunistic partner choice among arctic plants and root‐associated fungi is driven by environmental conditions

Ecological Monographs, Volume 95, Issue 3, August 2025.
Abstract Interactions between plants and soil microbes play a key role in structuring plant communities. In a rapidly changing Arctic environment, we urgently need to uncover how these interactions are responding to environmental changes. Here, we disentangle two contributions to variation in plant–fungus interactions along geographic and environmental
Bastien Parisy, Niels M. Schmidt, Alyssa R. Cirtwill, Edith Villa‐Galaviz, Mikko Tiusanen, Jukka Sirén, Cornelya F. C. Klütsch, Paul Eric Aspholm, Katrine Raundrup, Eero J. Vesterinen, Helena Wirta, Tomas Roslin   +11 more
wiley   +1 more source

Conformal Hypergraphs: Duality and Implications for the Upper Clique Transversal Problem

Journal of Graph Theory, Volume 109, Issue 4, Page 466-480, August 2025.
ABSTRACT Given a hypergraph ℋ, the dual hypergraph of ℋ is the hypergraph of all minimal transversals of ℋ. The dual hypergraph is always Sperner, that is, no hyperedge contains another. A special case of Sperner hypergraphs are the conformal Sperner hypergraphs, which correspond to the families of maximal cliques of graphs.
Endre Boros, Vladimir Gurvich, Martin Milanič, Yushi Uno   +3 more
wiley   +1 more source