{ "id": "0907.0897", "version": "v2", "published": "2009-07-05T22:44:28.000Z", "updated": "2009-08-18T11:31:39.000Z", "title": "Diffusion approximation for the components in critical inhomogeneous random graphs of rank 1", "authors": [ "Tatyana S. Turova" ], "comment": "Version 2: Added reference and correction", "categories": [ "math.PR" ], "abstract": "Consider the random graph on $n$ vertices $1, ..., n$. Each vertex $i$ is assigned a type $X_i$ with $X_1, ..., X_n$ being independent identically distributed as a nonnegative discrete random variable $X$. We assume that ${\\bf E} X^3<\\infty$. Given types of all vertices, an edge exists between vertices $i$ and $j$ independent of anything else and with probability $\\min \\{1, \\frac{X_iX_j}{n}(1+\\frac{a}{n^{1/3}}) \\}$. We study the critical phase, which is known to take place when ${\\bf E} X^2=1$. We prove that normalized by $n^{-2/3}$ the asymptotic joint distributions of component sizes of the graph equals the joint distribution of the excursions of a reflecting Brownian motion $B^a(s)$ with diffusion coefficient $\\sqrt{{\\bf E}X{\\bf E}X^3}$ and drift $a-\\frac{{\\bf E}X^3}{{\\bf E}X}s$. This shows that finiteness of ${\\bf E}X^3$ is the necessary condition for the diffusion limit. In particular, we conclude that the size of the largest connected component is of order $n^{2/3}$.", "revisions": [ { "version": "v2", "updated": "2009-08-18T11:31:39.000Z" } ], "analyses": { "subjects": [ "60C05", "60G42" ], "keywords": [ "critical inhomogeneous random graphs", "diffusion approximation", "asymptotic joint distributions", "discrete random", "largest connected component" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0907.0897T" } } }