2008/04/29 by Krivelevich, Michael, Lubetzky, Eyal, Sudakov, Benny · 2 citations
#05C80 #60C05 #Combinatorics (math.CO) #FOS: Mathematics #Probability (math.PR)
paper · doi:10.48550/arxiv.0804.4707
In this paper we analyze the appearance of a Hamilton cycle in the following random process. The process starts with an empty graph on n labeled vertices. At each round we are presented with K=K(n) edges, chosen uniformly at random from the missing ones, and are asked to add one of them to the current graph. The goal is to create a Hamilton cycle as soon as possible. We show that this problem has three regimes, depending on the value of K. For K=o(log n), the threshold for Hamiltonicity is (1+o(1))nlog n /(2K), i.e., typically we can construct a Hamilton cycle K times faster that in the usual random graph process. When K=ω(log n) we can essentially waste almost no edges, and create a Hamilton cycle in n+o(n) rounds with high probability. Finally, in the intermediate regime where K=Θ(log n), the threshold has order n and we obtain upper and lower bounds that differ by a multiplicative factor of 3.