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The Cartesian product of hypergraphs

โœ Scribed by Lydia Ostermeier; Marc Hellmuth; Peter F. Stadler


Publisher
John Wiley and Sons
Year
2011
Tongue
English
Weight
236 KB
Volume
70
Category
Article
ISSN
0364-9024

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โœฆ Synopsis


Abstract

We show that every simple, (weakly) connected, possibly directed and infinite, hypergraph has a unique prime factor decomposition with respect to the (weak) Cartesian product, even if it has infinitely many factors. This generalizes previous results for graphs and undirected hypergraphs to directed and infinite hypergraphs. The proof adopts the strategy outlined by Imrich and ลฝerovnik for the case of graphs and introduces the notion of diagonalโ€free grids as a replacement of the chordโ€free 4โ€cycles that play a crucial role in the case of graphs. This leads to a generalization of relation ฮ” on the arc set, whose convex hull is shown to coincide with the product relation of the prime factorization. ยฉ 2011 Wiley Periodicals, Inc. J Graph Theory


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