{ "id": "1412.4837", "version": "v1", "published": "2014-12-15T23:37:39.000Z", "updated": "2014-12-15T23:37:39.000Z", "title": "Abelian sandpile model and Biggs-Merino polynomial for directed graphs", "authors": [ "Swee Hong Chan" ], "comment": "28 pages+ Appendix, 5 figures", "categories": [ "math.CO" ], "abstract": "This paper is motivated by the result of Merino L{\\'o}pez that for an undirected graph G and a specified sink s, the Biggs-Merino polynomial, which is defined as a generating function of recurrent configurations of abelian sandpile model with sink, is equal to the Tutte polynomial of G. Perrot and Pham extended the definition of Biggs-Merino polynomial to directed graphs and conjectured that this polynomial is independent of the choice of sink. In this paper, we give a proof of the conjecture of Perrot and Pham, and answer the conjecture with an affirmative answer. We also observe that the Biggs-Merino polynomial is equal to the greedoid Tutte polynomial when G is an Eulerian digraph, generalizing Merino's Theorem to the setting of Eulerian digraphs.", "revisions": [ { "version": "v1", "updated": "2014-12-15T23:37:39.000Z" } ], "analyses": { "subjects": [ "05C30", "05C31" ], "keywords": [ "abelian sandpile model", "biggs-merino polynomial", "directed graphs", "eulerian digraph", "conjecture" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1412.4837C" } } }