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Independent Transversals in Sparse Partite Hypergraphs

Published online by Cambridge University Press:  12 September 2008

Paul Erdős
Affiliation:
Institute of Mathematics, Hungarian Academy of Sciences
András Gyárfás
Affiliation:
Computer and Automation Institute, Hungarian Academy of Sciences
Tomasz Łuczak
Affiliation:
Mathematical Institute, Polish Academy of Sciences

Abstract

An [n, k, r]-hypergraph is a hypergraph = (V, E) whose vertex set V is partitioned into n k-element sets V1, V2,…, Vn and for which, for each choice of r indices, 1 ≤ i1 < i2 < … < irn, there is exactly one edge eE such that |eVi| = 1 if i ∈ {i1, i2.…, ir} and otherwise |eVi| = 0. An independent transversal of an [n, k, r]-hypergraph is a set T = {a1, a2,…, an} ⊆ V such that aiVi for i = 1, 2, …, n and eT for all eE. The purpose of this note is to estimate fr(k), defined as the largest n for which any [n, k, r]-hypergraph has an independent transversal. The sharpest results are for r = 2 and for the case when k is small compared to r.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1994

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