English

Cyclic to Random Transposition Shuffles

Probability 2012-04-11 v1 Combinatorics

Abstract

Consider a permutation σSn\sigma\in S_n as a deck of cards numbered from 1 to nn and laid out in a row, where σj\sigma_j denotes the number of the card that is in the jj-th position from the left.\rm\ We define two cyclic to random transposition shuffles. The first one works as follows: for j=1,...,nj=1,..., n, on the jj-th step transpose the card that was \it originally\rm\ the jj-th from the left with a random card (possibly itself). The second shuffle works as follows: on the jj-th step, transpose the card that is \it currently\rm\ in the jj-th position from the left with a random card (possibly itself). For these shuffles, for each b[0,1]b\in[0,1], we calculate explicitly the limiting rescaled density function of x,0x1x,0\le x\le1, for the probability that a card with a number around bnbn ends up in a position around xnxn, and for each x[0,1]x\in[0,1], we calculate the limiting rescaled density function of b,0b1b,0\le b\le 1, for the probability that the card in a position around xnxn will be a card with a number around bnbn. These density functions all have a discontinuity at x=bx=b, and for each of them, the supremum of the density is obtained by approaching the discontinuity from one side, and, for certain values of the parameter, the infimum of the density is obtained by approaching the discontinuity from the other side.

Keywords

Cite

@article{arxiv.1204.2081,
  title  = {Cyclic to Random Transposition Shuffles},
  author = {Ross G. Pinsky},
  journal= {arXiv preprint arXiv:1204.2081},
  year   = {2012}
}
R2 v1 2026-06-21T20:47:10.956Z