{ "id": "1305.2206", "version": "v2", "published": "2013-05-09T20:13:43.000Z", "updated": "2015-11-24T21:15:05.000Z", "title": "Symmetries of statistics on lattice paths between two boundaries", "authors": [ "Sergi Elizalde", "Martin Rubey" ], "comment": "Small typos corrected, and journal reference and grant info added", "journal": "Adv. Math. 287 (2016), 347-388", "doi": "10.1016/j.aim.2015.09.025", "categories": [ "math.CO" ], "abstract": "We prove that on the set of lattice paths with steps N=(0,1) and E=(1,0) that lie between two fixed boundaries T and B (which are themselves lattice paths), the statistics `number of E steps shared with B' and `number of E steps shared with T' have a symmetric joint distribution. To do so, we give an involution that switches these statistics, preserves additional parameters, and generalizes to paths that contain steps S=(0,-1) at prescribed x-coordinates. We also show that a similar equidistribution result for path statistics follows from the fact that the Tutte polynomial of a matroid is independent of the order of its ground set. We extend the two theorems to k-tuples of paths between two boundaries, and we give some applications to Dyck paths, generalizing a result of Deutsch, to watermelon configurations, to pattern-avoiding permutations, and to the generalized Tamari lattice. Finally, we prove a conjecture of Nicol\\'as about the distribution of degrees of k consecutive vertices in k-triangulations of a convex n-gon. To achieve this goal, we provide a new statistic-preserving bijection between certain k-tuples of non-crossing paths and k-flagged semistandard Young tableaux, which is based on local moves reminiscent of jeu de taquin.", "revisions": [ { "version": "v1", "updated": "2013-05-09T20:13:43.000Z", "abstract": "We prove that on the set of lattice paths with steps N=(0,1) and E=(1,0) that lie between two boundaries T and B, the statistics 'number of E steps shared with B' and 'number of E steps shared with T' have a symmetric joint distribution. We give an involution that switches these statistics, preserves additional parameters, and generalizes to paths that contain steps S=(0,-1) at prescribed x-coordinates. We also show that a similar equidistribution result for path statistics follows from the fact that the Tutte polynomial of a matroid is independent of the order of its ground set. We extend the two theorems to k-tuples of paths between two boundaries, and we give some applications to Dyck paths, generalizing a result of Deutsch, to watermelon configurations, and to pattern-avoiding permutations. Finally, we prove a conjecture of Nicol\\'as about the distribution of degrees of k consecutive vertices in a k-triangulation of a convex n-gon, by providing a new bijection between certain k-tuples of paths and k-flagged semistandard Young tableaux.", "comment": null, "journal": null, "doi": null }, { "version": "v2", "updated": "2015-11-24T21:15:05.000Z" } ], "analyses": { "subjects": [ "05A19", "52C05", "05A15", "05B35", "05E05" ], "keywords": [ "lattice paths", "boundaries", "symmetries", "similar equidistribution result", "preserves additional parameters" ], "tags": [ "journal article" ], "publication": { "publisher": "Elsevier", "journal": "Adv. Math." }, "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1305.2206E" } } }