An application of principal bundles to coloring of graphs and hypergraphs

Milgram, James R.; Zvengrowski, Peter

  • Proceedings of the Winter School "Geometry and Physics", Publisher: Circolo Matematico di Palermo(Palermo), page [161]-167

Abstract

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An interesting connection between the chromatic number of a graph G and the connectivity of an associated simplicial complex N ( G ) , its “neighborhood complex”, was found by Lovász in 1978 (cf. L. Lovász [J. Comb. Theory, Ser. A 25, 319-324 (1978; Zbl 0418.05028)]). In 1986 a generalization to the chromatic number of a k -uniform hypergraph H , for k an odd prime, using an associated simplicial complex C ( H ) , was found ([N. Alon, P. Frankl and L. Lovász, Trans. Am. Math. Soc. 298, 359-370 (1986; Zbl 0605.05033)], Prop. 2.1). It was already noted in the above mentioned papers that there is an action of Z / 2 on N ( G ) , and of Z / k on C ( H ) , for any graph G and any k -uniform hypergraph H , k 2 (a 2-uniform hypergraph is just a graph). In this note we take advantage of this action to construct an associated principal ( Z / k ) -bundle ξ , and state theorems relating the chromatic number of the graph or hypergraph to!

How to cite

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Milgram, James R., and Zvengrowski, Peter. "An application of principal bundles to coloring of graphs and hypergraphs." Proceedings of the Winter School "Geometry and Physics". Palermo: Circolo Matematico di Palermo, 1994. [161]-167. <http://eudml.org/doc/221367>.

@inProceedings{Milgram1994,
abstract = {An interesting connection between the chromatic number of a graph $G$ and the connectivity of an associated simplicial complex $N(G)$, its “neighborhood complex”, was found by Lovász in 1978 (cf. L. Lovász [J. Comb. Theory, Ser. A 25, 319-324 (1978; Zbl 0418.05028)]). In 1986 a generalization to the chromatic number of a $k$-uniform hypergraph $H$, for $k$ an odd prime, using an associated simplicial complex $C(H)$, was found ([N. Alon, P. Frankl and L. Lovász, Trans. Am. Math. Soc. 298, 359-370 (1986; Zbl 0605.05033)], Prop. 2.1). It was already noted in the above mentioned papers that there is an action of $Z/2$ on $N(G)$, and of $Z/k$ on $C(H)$, for any graph $G$ and any $k$-uniform hypergraph $H$, $k \ge 2$ (a 2-uniform hypergraph is just a graph). In this note we take advantage of this action to construct an associated principal $(Z/k)$-bundle $\xi $, and state theorems relating the chromatic number of the graph or hypergraph to!},
author = {Milgram, James R., Zvengrowski, Peter},
booktitle = {Proceedings of the Winter School "Geometry and Physics"},
keywords = {Proceedings; Winter School; Zdíkov (Czech Republic); Geometry; Physics},
location = {Palermo},
pages = {[161]-167},
publisher = {Circolo Matematico di Palermo},
title = {An application of principal bundles to coloring of graphs and hypergraphs},
url = {http://eudml.org/doc/221367},
year = {1994},
}

TY - CLSWK
AU - Milgram, James R.
AU - Zvengrowski, Peter
TI - An application of principal bundles to coloring of graphs and hypergraphs
T2 - Proceedings of the Winter School "Geometry and Physics"
PY - 1994
CY - Palermo
PB - Circolo Matematico di Palermo
SP - [161]
EP - 167
AB - An interesting connection between the chromatic number of a graph $G$ and the connectivity of an associated simplicial complex $N(G)$, its “neighborhood complex”, was found by Lovász in 1978 (cf. L. Lovász [J. Comb. Theory, Ser. A 25, 319-324 (1978; Zbl 0418.05028)]). In 1986 a generalization to the chromatic number of a $k$-uniform hypergraph $H$, for $k$ an odd prime, using an associated simplicial complex $C(H)$, was found ([N. Alon, P. Frankl and L. Lovász, Trans. Am. Math. Soc. 298, 359-370 (1986; Zbl 0605.05033)], Prop. 2.1). It was already noted in the above mentioned papers that there is an action of $Z/2$ on $N(G)$, and of $Z/k$ on $C(H)$, for any graph $G$ and any $k$-uniform hypergraph $H$, $k \ge 2$ (a 2-uniform hypergraph is just a graph). In this note we take advantage of this action to construct an associated principal $(Z/k)$-bundle $\xi $, and state theorems relating the chromatic number of the graph or hypergraph to!
KW - Proceedings; Winter School; Zdíkov (Czech Republic); Geometry; Physics
UR - http://eudml.org/doc/221367
ER -

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