



01212nas a2200145   4500008004100000245007400041210006900115260001400184490000700198520074500205100002300950700002400973700002500997856004401022       2001                        eng d00aExact sampling from non-attractive distributions using summary states0 aExact sampling from nonattractive distributions using summary st  c2001/2/220 v633 a  Propp and Wilson's method of coupling from the past allows one to efficiently
generate exact samples from attractive statistical distributions (e.g., the
ferromagnetic Ising model). This method may be generalized to non-attractive
distributions by the use of summary states, as first described by Huber. Using
this method, we present exact samples from a frustrated antiferromagnetic
triangular Ising model and the antiferromagnetic q=3 Potts model. We discuss
the advantages and limitations of the method of summary states for practical
sampling, paying particular attention to the slowing down of the algorithm at
low temperature. In particular, we show that such a slowing down can occur in
the absence of a physical phase transition.
1 aChilds, Andrew, M.1 aPatterson, Ryan, B.1 aMacKay, David, J. C.  uhttp://arxiv.org/abs/cond-mat/0005132v1