{ "id": "1506.06819", "version": "v1", "published": "2015-06-22T23:37:00.000Z", "updated": "2015-06-22T23:37:00.000Z", "title": "Simplicial and Cellular Trees", "authors": [ "Art M. Duval", "Caroline J. Klivans", "Jeremy L. Martin" ], "comment": "39 pages (including 5-page bibliography); 5 figures. Chapter for forthcoming IMA volume \"Recent Trends in Combinatorics\"", "categories": [ "math.CO" ], "abstract": "Much information about a graph can be obtained by studying its spanning trees. On the other hand, a graph can be regarded as a 1-dimensional cell complex, raising the question of developing a theory of trees in higher dimension. As observed first by Bolker, Kalai and Adin, and more recently by numerous authors, the fundamental topological properties of a tree --- namely acyclicity and connectedness --- can be generalized to arbitrary dimension as the vanishing of certain cellular homology groups. This point of view is consistent with the matroid-theoretic approach to graphs, and yields higher-dimensional analogues of classical enumerative results including Cayley's formula and the matrix-tree theorem. A subtlety of the higher-dimensional case is that enumeration must account for the possibility of torsion homology in trees, which is always trivial for graphs. Cellular trees are the starting point for further high-dimensional extensions of concepts from algebraic graph theory including the critical group, cut and flow spaces, and discrete dynamical systems such as the abelian sandpile model.", "revisions": [ { "version": "v1", "updated": "2015-06-22T23:37:00.000Z" } ], "analyses": { "subjects": [ "05E45" ], "keywords": [ "cellular trees", "simplicial", "algebraic graph theory", "yields higher-dimensional analogues", "cellular homology groups" ], "note": { "typesetting": "TeX", "pages": 39, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150606819D" } } }