{ "id": "1605.07598", "version": "v1", "published": "2016-05-24T19:47:43.000Z", "updated": "2016-05-24T19:47:43.000Z", "title": "Ellipses Percolation", "authors": [ "Augusto Teixeira", "Daniel Ungaretti" ], "comment": "29 pages, 5 figures", "categories": [ "math.PR" ], "abstract": "We define a continuum percolation model that provides a collection of random ellipses on the plane and study the behavior of the covered set and the vacant set, the one obtained by removing all ellipses. Our model generalizes a construction that appears implicitly in the Poisson cylinder model of Tykesson and Windisch. The ellipses model has a parameter $\\alpha > 0$ associated with the tail decay of the major axis distribution; we only consider distributions $\\rho$ satisfying $\\rho[r, \\infty) \\asymp r^{-\\alpha}$. We prove that this model presents a double phase transition in $\\alpha$. For $\\alpha \\in (0,1]$ the plane is completely covered by the ellipses, almost surely. For $\\alpha \\in (1,2)$ the vacant set is not empty but does not percolate for any positive density of ellipses, while the covered set always percolates. For $\\alpha \\in (2, \\infty)$ the vacant set percolates for small densities of ellipses and the covered set percolates for large densities. Moreover, we prove for the critical parameter $\\alpha = 2$ that there is a non-degenerate interval of density for which the probability of crossing boxes of a fixed proportion is bounded away from zero and one, a rather unusual phenomenon. In this interval neither the covered set nor the vacant set percolate, a behavior that is similar to critical independent percolation on $\\mathbb{Z}^2$.", "revisions": [ { "version": "v1", "updated": "2016-05-24T19:47:43.000Z" } ], "analyses": { "subjects": [ "60K35", "82B43", "60G55" ], "keywords": [ "ellipses percolation", "vacant set percolate", "continuum percolation model", "poisson cylinder model", "major axis distribution" ], "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable" } } }