{ "id": "2002.09059", "version": "v1", "published": "2020-02-20T23:18:55.000Z", "updated": "2020-02-20T23:18:55.000Z", "title": "Three steps mixing for general random walks on the hypercube at criticality", "authors": [ "Andrea Collevecchio", "Robert Griffiths" ], "comment": "27 pages, 1 figure", "categories": [ "math.PR" ], "abstract": "We introduce a general class of random walks on the $N$-hypercube, study cut-off for the mixing time, and provide several types of representation for the transition probabilities. We observe that for a sub-class of these processes with long range (i.e. non-local) there exists a critical value of the range that allows an \"almost-perfect\" mixing in at most three steps. In other words, the total variation distance between the three steps transition and the stationary distribution decreases geometrically in $N$, which is the dimension of the hypercube. In some cases, the walk mixes almost-perfectly in exactly two steps. Notice that a well-known result (Theorem 1 in Diaconis and Shahshahani (1986)) shows that there exist no random walk on Abelian groups (such as the hypercube) which mixes perfectly in exactly two steps.", "revisions": [ { "version": "v1", "updated": "2020-02-20T23:18:55.000Z" } ], "analyses": { "subjects": [ "60J10" ], "keywords": [ "general random walks", "steps mixing", "criticality", "total variation distance", "stationary distribution decreases" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable" } } }