Results 41 to 50 of about 35,860 (197)
Obstructions for Homomorphisms to Odd Cycles in Series‐Parallel Graphs
Journal of Graph Theory, EarlyView.ABSTRACT For a graph H $H$, an H $H$‐colouring of a graph G $G$ is a vertex mapping ϕ : V ( G ) → V ( H ) $\phi :V(G)\to V(H)$ such that adjacent vertices are mapped to adjacent vertices. A graph G $G$ is C 2 k + 1 ${C}_{2k+1}$‐critical if G $G$ has no C 2 k + 1 ${C}_{2k+1}$‐colouring but every proper subgraph of G $G$ has a C 2 k + 1 ${C}_{2k+1 ...
Eun‐Kyung Cho +3 more
wiley +1 more source
Extremal, enumerative and probabilistic results on ordered hypergraph matchings
Forum of Mathematics, SigmaAn ordered r-matching is an r-uniform hypergraph matching equipped with an ordering on its vertices. These objects can be viewed as natural generalisations of r-dimensional orders.
Michael Anastos +3 more
doaj +1 more source
DiskScissors: Cutting Arbitrary‐Topology Solids for Bijective Mapping
Computer Graphics Forum, EarlyView.Abstract An algorithm for cutting solid objects in a topology‐controlled manner is presented. Concretely, given a loop on the object boundary, a disk‐topology cut surface bounded by the loop is constructed in the interior. In contrast to various previous approaches, both disk topology and conformance to the prescribed loop are ensured by construction ...
S. Hinderink, M. Campen
wiley +1 more source
Machine Learning for Synthetic Organic Chemistry: Methods, Applications, and Best Practices
Angewandte Chemie Novit, Volume 2, Issue 3, September 2026.Artificial intelligence (AI) and machine learning (ML) are increasingly reshaping experimental chemistry. This review maps the challenges of synthetic organic chemistry to modern digital tools that can help address them. While focusing on the practical application of ML tools in real‐world laboratory settings, we outline prerequisites, emerging ...
Niklas Hölter +3 more
wiley +1 more source
Orientations of Graphs With at Most One Directed Path Between Every Pair of Vertices
Journal of Graph Theory, Volume 113, Issue 1, Page 143-164, September 2026.ABSTRACT Given a graph G, we say that an orientation D of G is a KT orientation if, for all u , v ∈ V ( D ), there is at most one directed path (in any direction) between u and v. Graphs that admit such orientations have been used to construct graphs with large chromatic number and small clique number that served as counterexamples to various ...
Barbora Dohnalová +3 more
wiley +1 more source
Majority Dynamics on Finite Trees
Random Structures &Algorithms, Volume 69, Issue 2, September 2026.ABSTRACT For an arbitrary finite tree T$$ T $$, we find the exact value of the worst‐case stabilization time of majority dynamics on T$$ T $$. We also prove that for a perfect rooted cubic tree T$$ T $$ with diameter D$$ D $$ and uniformly random initial opinions, the dynamics stabilizes in time τ∈(D/4,D/3)$$ \tau \in \left(D/4,D/3\right) $$ with high ...
Itai Benjamini +2 more
wiley +1 more source
On Kotzig's Perfect Set Problem of Hamiltonian Cycle Decompositions of the Complete Graph
Journal of Combinatorial Designs, Volume 34, Issue 8, Page 388-409, August 2026.ABSTRACT A Hamiltonian cycle decomposition (HCD) of K n is a set of Hamiltonian cycles in which each 1‐path of K n appears exactly once. A Dudeney set of K n is a set of Hamiltonian cycles in which each 2‐path of K n appears exactly once. Kotzig's perfect set of HCDs of K n is a set of HCDs whose union forms a Dudeney set.
Nobuaki Mutoh
wiley +1 more source
C-Finite Sequences and Riordan Arrays
MathematicsMany prominent combinatorial sequences, such as the Fibonacci, Lucas, Pell, Jacobsthal and Tribonacci sequences, are defined by homogeneous linear recurrence relations with constant coefficients.
Donatella Merlini
doaj +1 more source
On Strongly and Robustly Critical Graphs
Journal of Graph Theory, Volume 112, Issue 4, Page 469-483, August 2026.ABSTRACT In extremal combinatorics, it is common to focus on structures that are minimal with respect to a certain property. In particular, critical and list‐critical graphs occupy a prominent place in graph coloring theory. Stiebitz, Tuza, and Voigt introduced strongly critical graphs, i.e., graphs that are k‐critical yet L‐colorable with respect to ...
Anton Bernshteyn +3 more
wiley +1 more source
Asymmetric Results About Graph Homomorphisms
Random Structures &Algorithms, Volume 69, Issue 1, August 2026.ABSTRACT Many important results in extremal graph theory can be roughly summarized as “if a triangle‐free graph G$$ G $$ has certain properties, then it has a homomorphism to a triangle‐free graph Γ$$ \Gamma $$ of bounded size.” For example, bounds on homomorphism thresholds give such a statement if G$$ G $$ has sufficiently high minimum degree, and ...
Lior Gishboliner +2 more
wiley +1 more source