{ "id": "2108.04989", "version": "v1", "published": "2021-08-11T02:04:13.000Z", "updated": "2021-08-11T02:04:13.000Z", "title": "Random increasing plane trees: asymptotic enumeration of vertices by distance from leaves", "authors": [ "Miklós Bóna", "Boris Pittel" ], "comment": "20 pages", "categories": [ "math.CO" ], "abstract": "We prove that for any fixed $k$, the probability that a random vertex of a random increasing plane tree is of rank $k$, i.e. at vertex-distance $k$ from the leaves, converges to a constant $c_k$ as the size $n$ of the tree goes to infinity. We prove a similar result for randomly selected $r$-tuples of vertices that shows that the ranks of a finite uniformly random set of vertices are asymptotically independent. We compute the exact value of $c_k$ for $0\\leq k\\leq 3$, demonstrating that the limiting expected fraction of vertices with rank $\\le 3$ is $0.9997\\dots$. In general, the distribution $\\{c_k\\}$ is quasi-Poisson, i.e. $c_k=O(1/(k-2)!)$. We prove that with high probability, the highest rank of a vertex in the tree is sandwiched between $\\log n / (\\log(\\log n))$ and $1.5\\log n/(\\log(\\log n))$.", "revisions": [ { "version": "v1", "updated": "2021-08-11T02:04:13.000Z" } ], "analyses": { "subjects": [ "05A05", "05A15", "05A16", "05C05", "06B05", "05C80", "05D40", "60C05" ], "keywords": [ "random increasing plane tree", "asymptotic enumeration", "finite uniformly random set", "random vertex", "high probability" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }