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On Percolation and the Bunkbed Conjecture

Published online by Cambridge University Press:  17 February 2010

SVANTE LINUSSON
SVANTE LINUSSON*
Affiliation:
Department of Mathematics, KTH-Royal Institute of Technology, SE-100 44, Stockholm, Sweden (e-mail: linusson@math.kth.se)
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Abstract

We study a problem on edge percolation on product graphs G × K2. Here G is any finite graph and K2 consists of two vertices {0, 1} connected by an edge. Every edge in G × K2 is present with probability p independent of other edges. The bunkbed conjecture states that for all G and p, the probability that (u, 0) is in the same component as (v, 0) is greater than or equal to the probability that (u, 0) is in the same component as (v, 1) for every pair of vertices u, v ∈ G.

We generalize this conjecture and formulate and prove similar statements for randomly directed graphs. The methods lead to a proof of the original conjecture for special classes of graphs G, in particular outerplanar graphs.

Type
Paper
Information
Combinatorics, Probability and Computing , Volume 20 , Issue 1 , January 2011 , pp. 103 - 117
Copyright
Copyright © Cambridge University Press 2010

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