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Martin Snethlage

Publications and source records attributed to Martin Snethlage.

2 recordsLinked to original sources

Point field models for the galaxy point pattern. Modelling the singularity of the two-point correlation function

There is empirical evidence that the two-point correlation function of the galaxy distribution follows, for small scales, reasonably well a power-law expression $ξ(r)\propto r^{-γ}$ with $γ$ between 1.5 and 1.9. Nevertheless, most of the point field models suggested in the literature do not have this property. This paper presents a new class of models, which is produced by modifying point fields commonly used in cosmology to mimic the galaxy distribution, but where $γ=2$ is too large. The points are independently and randomly shifted, leading to the desired reduction of the value of $γ$.

astro-ph

Is Bootstrap Really Helpful in Point Process Statistics?

There are some papers which describe the use of bootstrap techniques in point process statistics. The aim of the present paper is to show that the form in which bootstrap is used there is dubious. In case of variance estimation of pair correlation function estimators the used bootstrap techniques lead to results which can be obtained simpler without simulation; furthermore, they differ from the desired results. The problem to obtain confidence regions for the intensity function of inhomogeneous Poisson processes can be easily solved without bootstrap techniques.

math.ST