4 research outputs found
A pattern theorem for random sorting networks
A sorting network is a shortest path from 12..n to n..21 in the Cayley graph
of the symmetric group S(n) generated by nearest-neighbor swaps. A pattern is a
sequence of swaps that forms an initial segment of some sorting network. We
prove that in a uniformly random n-element sorting network, any fixed pattern
occurs in at least cn^2 disjoint space-time locations, with probability tending
to 1 exponentially fast as n tends to infinity. Here c is a positive constant
which depends on the choice of pattern. As a consequence, the probability that
the uniformly random sorting network is geometrically realizable tends to 0.Comment: 21 pages, 9 figures. Final journal versio