{ "id": "1009.5162", "version": "v1", "published": "2010-09-27T05:36:01.000Z", "updated": "2010-09-27T05:36:01.000Z", "title": "Bounds on the Rubbling and Optimal Rubbling Numbers of Graphs", "authors": [ "Gyula Y. Katona", "Nandor Sieben" ], "categories": [ "math.CO" ], "abstract": "A pebbling move on a graph removes two pebbles at a vertex and adds one pebble at an adjacent vertex. Rubbling is a version of pebbling where an additional move is allowed. In this new move, one pebble each is removed at vertices $v$ and $w$ adjacent to a vertex $u$, and an extra pebble is added at vertex $u$. A vertex is reachable from a pebble distribution if it is possible to move a pebble to that vertex using rubbling moves. The rubbling number is the smallest number $m$ needed to guarantee that any vertex is reachable from any pebble distribution of $m$ pebbles. The optimal rubbling number is the smallest number $m$ needed to guarantee a pebble distribution of $m$ pebbles from which any vertex is reachable. We give bounds for rubbling and optimal rubbling numbers. In particular, we find an upper bound for the rubbling number of $n$-vertex, diameter $d$ graphs, and estimates for the maximum rubbling number of diameter 2 graphs. We also give a sharp upper bound for the optimal rubbling number, and sharp upper and lower bounds in terms of the diameter.", "revisions": [ { "version": "v1", "updated": "2010-09-27T05:36:01.000Z" } ], "analyses": { "subjects": [ "05C99" ], "keywords": [ "optimal rubbling number", "pebble distribution", "smallest number", "sharp upper bound", "additional move" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1009.5162K" } } }