{ "id": "1006.1879", "version": "v4", "published": "2010-06-09T19:23:25.000Z", "updated": "2011-03-29T22:20:29.000Z", "title": "Dominating Sets in Triangulations on Surfaces", "authors": [ "Hong Liu", "Michael J. Pelsmajer" ], "comment": "26 pages, 12 figures; small fix", "categories": [ "math.CO" ], "abstract": "A dominating set D of a graph G is a set such that each vertex v of G is either in the set or adjacent to a vertex in the set. Matheson and Tarjan (1996) proved that any n-vertex plane triangulation has a dominating set of size at most n/3, and conjectured a bound of n/4 for n sufficiently large. King and Pelsmajer recently proved this for graphs with maximum degree at most 6. Plummer and Zha (2009) and Honjo, Kawarabayashi, and Nakamoto (2009) extended the n/3 bound to triangulations on surfaces. We prove two related results: (i) There is a constant c such that any n-vertex plane triangulation with maximum degree at most 6 has a dominating set of size at most n/6 + c. (ii) For any surface S, nonnegative t, and epsilon > 0, there exists C such that for any n-vertex triangulation on S with at most t vertices of degree other than 6, there is a dominating set of size at most n(1/6 + epsilon) + C. As part of the proof, we also show that any n-vertex triangulation of a non-orientable surface has a non-contractible cycle of length at most 2sqrt(n). Albertson and Hutchinson (1986) proved that for n-vertex triangulation of an orientable surface other than a sphere has a non-contractible cycle of length sqrt(2n), but no similar result was known for non-orientable surfaces.", "revisions": [ { "version": "v4", "updated": "2011-03-29T22:20:29.000Z" } ], "analyses": { "subjects": [ "05C10", "05C69" ], "keywords": [ "dominating set", "n-vertex plane triangulation", "n-vertex triangulation", "maximum degree", "non-orientable surface" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1006.1879L" } } }