{ "id": "1708.07671", "version": "v1", "published": "2017-08-25T09:54:00.000Z", "updated": "2017-08-25T09:54:00.000Z", "title": "Phase transitions in graphs on orientable surfaces", "authors": [ "Mihyun Kang", "Michael Moßhammer", "Philipp Sprüssel" ], "comment": "47 pages, 1 figure. An extended abstract of this paper has been published in the Proceedings of the European Conference on Combinatorics, Graph Theory and Applications (EuroComb17), Electronic Notes in Discrete Mathematics 61:687--693, 2017", "categories": [ "math.CO" ], "abstract": "Let $\\mathbb{S}_g$ be the orientable surface of genus $g$. We prove that the component structure of a graph chosen uniformly at random from the class $\\mathcal{S}_g(n,m)$ of all graphs on vertex set $[n]=\\{1,\\dotsc,n\\}$ with $m$ edges embeddable on $\\mathbb{S}_g$ features two phase transitions. The first phase transition mirrors the classical phase transition in the Erd\\H{o}s--R\\'enyi random graph $G(n,m)$ chosen uniformly at random from all graphs with vertex set $[n]$ and $m$ edges. It takes place at $m=\\frac{n}{2}+O(n^{2/3})$, when a unique largest component, the so-called \\emph{giant component}, emerges. The second phase transition occurs at $m = n+O(n^{3/5})$, when the giant component covers almost all vertices of the graph. This kind of phenomenon is strikingly different from $G(n,m)$ and has only been observed for graphs on surfaces. Moreover, we derive an asymptotic estimation of the number of graphs in $\\mathcal{S}_g(n,m)$ throughout the regimes of these two phase transitions.", "revisions": [ { "version": "v1", "updated": "2017-08-25T09:54:00.000Z" } ], "analyses": { "keywords": [ "orientable surface", "vertex set", "first phase transition mirrors", "second phase transition occurs", "giant component covers" ], "tags": [ "conference paper" ], "note": { "typesetting": "TeX", "pages": 47, "language": "en", "license": "arXiv", "status": "editable" } } }