7,260 research outputs found

    Central limit theorems for Poisson hyperplane tessellations

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    We derive a central limit theorem for the number of vertices of convex polytopes induced by stationary Poisson hyperplane processes in Rd\mathbb{R}^d. This result generalizes an earlier one proved by Paroux [Adv. in Appl. Probab. 30 (1998) 640--656] for intersection points of motion-invariant Poisson line processes in R2\mathbb{R}^2. Our proof is based on Hoeffding's decomposition of UU-statistics which seems to be more efficient and adequate to tackle the higher-dimensional case than the ``method of moments'' used in [Adv. in Appl. Probab. 30 (1998) 640--656] to treat the case d=2d=2. Moreover, we extend our central limit theorem in several directions. First we consider kk-flat processes induced by Poisson hyperplane processes in Rd\mathbb{R}^d for 0≤k≤d−10\le k\le d-1. Second we derive (asymptotic) confidence intervals for the intensities of these kk-flat processes and, third, we prove multivariate central limit theorems for the dd-dimensional joint vectors of numbers of kk-flats and their kk-volumes, respectively, in an increasing spherical region.Comment: Published at http://dx.doi.org/10.1214/105051606000000033 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Limit theorems for functionals on the facets of stationary random tessellations

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    We observe stationary random tessellations X={Ξn}n≥1X=\{\Xi_n\}_{n\ge1} in Rd\mathbb{R}^d through a convex sampling window WW that expands unboundedly and we determine the total (k−1)(k-1)-volume of those (k−1)(k-1)-dimensional manifold processes which are induced on the kk-facets of XX (1≤k≤d−11\le k\le d-1) by their intersections with the (d−1)(d-1)-facets of independent and identically distributed motion-invariant tessellations XnX_n generated within each cell Ξn\Xi_n of XX. The cases of XX being either a Poisson hyperplane tessellation or a random tessellation with weak dependences are treated separately. In both cases, however, we obtain that all of the total volumes measured in WW are approximately normally distributed when WW is sufficiently large. Structural formulae for mean values and asymptotic variances are derived and explicit numerical values are given for planar Poisson--Voronoi tessellations (PVTs) and Poisson line tessellations (PLTs).Comment: Published at http://dx.doi.org/10.3150/07-BEJ6131 in the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

    Lepton number violation in theories with a large number of Standard Model copies

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    We examine lepton number violation (LNV) in theories with a saturated black hole bound on a large number of species. Such theories have been advocated recently as a possible solution to the hierarchy problem and an explanation of the smallness of neutrino masses. The violation of lepton number can be a potential phenomenological problem of this N-copy extension of the Standard Model as due to the low quantum gravity scale black holes may induce TeV scale LNV operators generating unacceptably large rates of LNV processes. We show, however, that this does not happen in this scenario due to a specific compensation mechanism between contributions of different Majorana neutrino states to these processes. As a result rates of LNV processes are extremely small and far beyond experimental reach, at least for the left-handed neutrino states.Comment: 5 pages, 3 figure

    Asymptotic goodness-of-fit tests for the Palm mark distribution of stationary point processes with correlated marks

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    We consider spatially homogeneous marked point patterns in an unboundedly expanding convex sampling window. Our main objective is to identify the distribution of the typical mark by constructing an asymptotic χ2\chi^2-goodness-of-fit test. The corresponding test statistic is based on a natural empirical version of the Palm mark distribution and a smoothed covariance estimator which turns out to be mean square consistent. Our approach does not require independent marks and allows dependences between the mark field and the point pattern. Instead we impose a suitable β\beta-mixing condition on the underlying stationary marked point process which can be checked for a number of Poisson-based models and, in particular, in the case of geostatistical marking. In order to study test performance, our test approach is applied to detect anisotropy of specific Boolean models.Comment: Published in at http://dx.doi.org/10.3150/13-BEJ523 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm). arXiv admin note: substantial text overlap with arXiv:1205.504

    Lepton number, black hole entropy and 10 to the 32 copies of the Standard Model

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    Lepton number violating processes are a typical problem in theories with a low quantum gravity scale. In this paper we examine lepton number violation (LNV) in theories with a saturated black hole bound on a large number of species. Such theories have been advocated recently as a possible solution to the hierarchy problem and an explanation of the smallness of neutrino masses. Naively one would expect black holes to introduce TeV scale LNV operators, thus generating unacceptably large rates of LNV processes. We show, however, that this does not happen in this scenario due to a complicated compensation mechanism between contributions of different Majorana neutrino states to these processes. As a result rates of LNV processes are extremely small and far beyond experimental reach, at least for the left-handed neutrino states.Comment: 6 pages, 3 figures, to appear in Proc. PASCOS 2010, Valencia, Spai
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