Results 71 to 80 of about 514 (184)
On Oriented Colourings of Graphs on Surfaces
Journal 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
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Density of universal classes of series-parallel graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2005 A class of graphs $\mathcal{C}$ ordered by the homomorphism relation is universal if every countable partial order can be embedded in $\mathcal{C}$. It was shown in [ZH] that the class $\mathcal{C_k}$ of $k$-colorable graphs, for any fixed $k≥3$, induces
Jaroslav Nešetřil, Yared Nigussie
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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
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Groups with a finite Busemann boundary are virtually cyclic
Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.Abstract This note is a continuation of the study of the relationship between the geometry of Cayley graphs and the size of its metric‐functional boundary. We show that if there exists a Cayley graph with finitely many Busemann points, then the underlying group is virtually cyclic.
Corentin Bodart +2 more
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List Homomorphisms to Reflexive Graphs
Journal of Combinatorial Theory, Series B, 1998 Let \(H\) be a fixed graph. In analogy to list colouring problems, we introduce the following list homomorphism problem: Given an input graph \(G\) and for each vertex \(v\) of \(G\) a `list' \(L(v) \subseteq V(H)\), decide whether or not there is a homomorphism (edge-preserving mapping of vertices) \(f : G \to H\) such that \(f(v) \in L(v)\) for each \
Tomás Feder, Pavol Hell
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The oriented chromatic number of edge-amalgamation of cycle graph
Indonesian Journal of Combinatorics, 2019 An oriented k − coloring of an oriented graph G⃗ is a partition of V(G⃗) into k color classes such that no two adjacent vertices belong to the same color class, and all the arcs linking the two color classes have the same direction.
Dina Eka Nurvazly +2 more
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A birational description of the minimal exponent
Journal of the London Mathematical Society, Volume 114, Issue 2, August 2026.Abstract We give a description of the minimal exponent of a hypersurface using higher direct images of suitably twisted sheaves of log forms on a log resolution.
Qianyu Chen, Mircea Mustaţă
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Graph Homomorphisms for Quantum Players
, 2012 A homomorphism from a graph X to a graph Y is an adjacency preserving mapping f:V(X) -> V(Y). We consider a nonlocal game in which Alice and Bob are trying to convince a verifier with certainty that a graph X admits a homomorphism to Y. This is a generalization of the well-studied graph coloring game.
Mančinska, Laura, Roberson, David
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Finding an almost perfect matching in a hypergraph avoiding forbidden submatchings
Journal of the London Mathematical Society, Volume 114, Issue 2, August 2026.Abstract In 1973, Erdős conjectured the existence of high girth (n,3,2)$(n,3,2)$‐Steiner systems. Recently, Glock, Kühn, Lo, and Osthus and independently Bohman and Warnke proved the approximate version of Erdős' conjecture. Recently, Kwan, Sah, Sawhney, and Simkin proved Erdős' conjecture.
Michelle Delcourt, Luke Postle
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Fuzzy Number-Valued Fuzzy Graph [PDF]
Control and Optimization in Applied Mathematics, 2016 Graph theory has an important role in the area of applications of networks and clustering. In the case of dealing with uncertain data, we must utilize ambiguous data such as fuzzy value, fuzzy interval value or values of fuzzy number.
Siyamak Firouzian +1 more
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