Voronoi Tessellations and the Cosmic Web: Spatial Patterns and Clustering across the Universe

Abstract

The spatial cosmic matter distribution on scales of a few up to more than a hundred Megaparsec displays a salient and pervasive foamlike pattern. Voronoi tessellations are a versatile and flexible mathematical model for such weblike spatial patterns. They would be the natural asymptotic result of an evolution in which low-density expanding void regions dictate the spatial organization of the Megaparsec Universe, while matter assembles in high-density filamentary and wall-like interstices between the voids. We describe the results of ongoing investigations of a variety of aspects of cosmologically relevant spatial distributions and statistics within the framework of Voronoi tessellations. Particularly enticing is the finding of a profound scaling of both clustering strength and clustering extent for the distribution of tessellation nodes, suggestive for the clustering properties of galaxy clusters. Cellular patterns may be the source of an intrinsic ``geometrically biased'' clustering.Comment: 10 pages, 9 figures, accepted for publication as long paper in proceedings Fourth International Symposium on Voronoi Diagrams in Science and Engineering (ISVD 2007), ed. C. Gold, IEEE Computer Society, July 2007. For high-res version see http://www.astro.rug.nl/~weygaert/tim1publication/vorwey.isvd07.pd