Title
Orientability of random hypergraphs and the power of multiple choices
Abstract
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*, but fails doing so 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.
Year
DOI
Venue
2010
10.1007/978-3-642-14165-2_30
ICALP
Keywords
Field
DocType
graph hn,n vertex,critical quantity ck,multiple choice,hypergraph h,c ck,n location,random graph process,m edge,vertices v,k random vertex,random hypergraphs,phase transition,hash table,random graph,connected component
Discrete mathematics,Combinatorics,Random graph,Vertex (geometry),Hypergraph,Orientability,Constraint graph,Giant component,Degree (graph theory),Connected component,Mathematics
Conference
Volume
ISSN
ISBN
6198
0302-9743
3-642-14164-1
Citations 
PageRank 
References 
12
0.84
16
Authors
2
Name
Order
Citations
PageRank
Nikolaos Fountoulakis118518.04
Konstantinos Panagiotou229027.80