An introduction to covering problems for random walks on graphs
An introduction to covering problems for random walks on graphs
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介绍图上随机游走的问题
DOI:
10.1007/bf01048271
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发表时间:
1989
影响因子:
0.8
通讯作者:
D. Aldous
中科院分区:
文献类型:
--
作者:
D. Aldous
On a finite connected undirected graph G=(Vg) there is a natural notion of simple random walk: the Markov chain which from its current vertex v, jumps to one of the dv neighboring vertices with uniform probability. Such random walks have been studied in the literature from several viewpoints. Some consequences of classical Markov chain theory are discussed in Ref. 1; the analogy with electrical networks is treated in Ref. 2; and Ref. 3 describes connections with manifold theory. Our topic is motivated indirectly by certain computer science problems, surveyed by Broder and Karlin, below.Write T w for the first hitting time on vertex w, and C= maxw Tw for the covering time, that is, the number of steps taken to visit every vertex. The typical size of C depends on the graph: one can study C for specific graphs, and one can seek bounds on C in terms of graph-theoretic parameters of the graph G, an obvious parameter being the number of vertices I VI. The expectation E~, C depends on the starting vertex v, and at different places we consider the extreme cases max,, E~ C, min~ E~ C and the" average" case E~ C, where~ is the stationary distribution