Orientability of Random Hypergraphs and the Power of Multiple Choices
Orientability of Random Hypergraphs and the Power of Multiple Choices
复制标题
随机超图的可定向性和多重选择的力量
DOI:
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发表时间:
2010
期刊:
影响因子:
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通讯作者:
K. Panagiotou
中科院分区:
文献类型:
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作者:
N. Fountoulakis;K. Panagiotou
A hypergraph H = (V,E) is called s-orientable, if there is an assignment of each edge e ∈ E to one of its vertices v ∈ e such that no vertex is assigned more than s edges. Let Hn,m,k be a hypergraph, drawn uniformly at random from the set of all k-uniform hypergraphs with n vertices and m edges. In this paper we establish the threshold for the 1-orientability of Hn,m,k for all k ≥ 3, i.e., we determine a critical quantity ck* such that with probability 1 - o(1) the graph Hn,cn,k has a 1-orientation if c ck*.
We present two applications of this result that involve the paradigm of multiple choices. First, we show how it implies sharp load thresholds for cuckoo hash tables, where each element chooses k out of n locations. Particularly, for each k ≥ 3 we prove that with probability 1 - o(1) the maximum number of elements that can be hashed is (1 - o(1))ck*n, and more items prevent the successful allocation. Second, we study random graph processes, where in each step we have the choice among any edge connecting k random vertices. Here we show the existence of a phase transition for avoiding a giant connected component, and quantify precisely the dependence on k.
DOI:
10.1137/1.9781611973068.87
发表时间:
2009
期刊:
影响因子:
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作者:
Martin Dietzfelbinger;Ulf Schellbach
通讯作者:
Ulf Schellbach