AbstractA class C of graphs is said to be H-bounded if each graph in the class C admits a homomorphism to H. We give a general necessary and sufficient condition for the existence of bounds with special local properties. This gives a new proof of the Häggkvist–Hell theorem [R. Häggkvist, P. Hell, Universality of A-mote graphs, European J. Combin. 14 (1993) 23–27] and implies several cases of the existence of triangle free bounds for planar graphs
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
AbstractWe study restricted homomorphism dualities in the context of classes with bounded expansion ...
AbstractA class C of graphs is said to be H-bounded if each graph in the class C admits a homomorphi...
Abstract. A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective ...
A homomorphism from a graph G to a graph H is locally bijective, injective, or surjective if its res...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
A graph property is any isomorphism closed class of simple graphs. For a simple finite graph H, let ...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
We consider constrained variants of graph homomorphisms such as embeddings, monomorphisms, full homo...
We consider constrained variants of graph homomorphisms such as embeddings, monomorphisms, full homo...
AbstractIn the course of extending Grötzsch’s Theorem, we prove that every triangle-free graph witho...
A graph is H-free if it has no induced subgraph isomorphic to H. We continue a study into the bounde...
A graph is H-free if it has no induced subgraph isomorphic to H. We continue a study into the bounde...
Counting homomorphisms from a graph H into another graph G is a fundamental problem of (parameterize...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
AbstractWe study restricted homomorphism dualities in the context of classes with bounded expansion ...
AbstractA class C of graphs is said to be H-bounded if each graph in the class C admits a homomorphi...
Abstract. A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective ...
A homomorphism from a graph G to a graph H is locally bijective, injective, or surjective if its res...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
A graph property is any isomorphism closed class of simple graphs. For a simple finite graph H, let ...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
We consider constrained variants of graph homomorphisms such as embeddings, monomorphisms, full homo...
We consider constrained variants of graph homomorphisms such as embeddings, monomorphisms, full homo...
AbstractIn the course of extending Grötzsch’s Theorem, we prove that every triangle-free graph witho...
A graph is H-free if it has no induced subgraph isomorphic to H. We continue a study into the bounde...
A graph is H-free if it has no induced subgraph isomorphic to H. We continue a study into the bounde...
Counting homomorphisms from a graph H into another graph G is a fundamental problem of (parameterize...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its res...
AbstractWe study restricted homomorphism dualities in the context of classes with bounded expansion ...
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