{ "id": "2011.14604", "version": "v1", "published": "2020-11-30T08:05:12.000Z", "updated": "2020-11-30T08:05:12.000Z", "title": "Factor of i.i.d. processes and Cayley diagrams", "authors": [ "Riley Thornton" ], "categories": [ "math.CO", "math.DS", "math.LO" ], "abstract": "We investigate when a $\\Gamma$-f.i.i.d. solution (or approximate solution) to a local labelling problem on a Cayley graph $G=\\operatorname{Cay}(\\Gamma, E)$ lifts to an $\\operatorname{Aut}(G)$-f.i.i.d. solution (or approximate solution). A Cayley diagram is an edge labelling of $G$ by elements of the generating set $E$ so that the cycles correspond exactly to paths labelled by relations in $\\Gamma$. We show that if $G$ admits an $\\operatorname{Aut}(G)$-f.i.i.d. (approximate) Cayley diagram, then any $\\Gamma$-f.i.i.d. (approximate) solution to a local combinatorial problem lifts to $\\operatorname{Aut}(G)$-f.i.i.d. (approximate) solution. We also establish a number of results on which graphs admit such a Cayley diagram. We show that Cayley graphs of amenable groups and free groups always admit $\\operatorname{Aut}(G)$-f.i.i.d. approximate Cayley diagrams, and that torsion-free nilpotent groups never admit nontrivial $\\operatorname{Aut}(G)$-f.i.i.d. Cayley diagrams. Finally, we construct a Cayley graph with a $\\Gamma$-f.i.i.d. 3-colorings that does not lift to even an approximate $\\operatorname{Aut}(G)$-f.i.i.d. 3-coloring. Our construction also answers a question of Weilacher.", "revisions": [ { "version": "v1", "updated": "2020-11-30T08:05:12.000Z" } ], "analyses": { "subjects": [ "37A50", "03E15", "05C63" ], "keywords": [ "cayley graph", "local combinatorial problem lifts", "approximate solution", "approximate cayley diagrams", "torsion-free nilpotent groups" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }