A note on intersecting hypergraphs with large cover number

We give a construction of r-partite r-uniform intersecting hypergraphs with cover number at least r − 4 for all but finitely many r. This answers a question of Abu-Khazneh, Barát, Pokrovskiy and Szabó, and shows that a long-standing unsolved conjecture due to Ryser is close to being best possible fo...

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Detalles Bibliográficos
Main Authors: Haxell, P, Scott, A
Formato: Journal article
Publicado: Electronic Journal of Combinatorics 2017
Descripción
Summary:We give a construction of r-partite r-uniform intersecting hypergraphs with cover number at least r − 4 for all but finitely many r. This answers a question of Abu-Khazneh, Barát, Pokrovskiy and Szabó, and shows that a long-standing unsolved conjecture due to Ryser is close to being best possible for every value of r.