Distinguishing graphs by the number of homomorphisms
Discussiones Mathematicae. Graph Theory, Tome 15 (1995) no. 1, pp. 73-75
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A homomorphism from one graph to another is a map that sends vertices to vertices and edges to edges. We denote the number of homomorphisms from G to H by |G → H|. If is a collection of graphs, we say that distinguishes graphs G and H if there is some member X of such that |G → X | ≠ |H → X|. is a distinguishing family if it distinguishes all pairs of graphs.
Keywords:
graph homomorphism, chromatic number
@article{DMGT_1995_15_1_a7,
author = {Fisk, Steve},
title = {Distinguishing graphs by the number of homomorphisms},
journal = {Discussiones Mathematicae. Graph Theory},
pages = {73--75},
year = {1995},
volume = {15},
number = {1},
language = {en},
url = {http://geodesic.mathdoc.fr/item/DMGT_1995_15_1_a7/}
}
Fisk, Steve. Distinguishing graphs by the number of homomorphisms. Discussiones Mathematicae. Graph Theory, Tome 15 (1995) no. 1, pp. 73-75. http://geodesic.mathdoc.fr/item/DMGT_1995_15_1_a7/
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