The Shape, Multiplicity, and Evolution of Superclusters in ΛCDM Cosmology

We determine the shape, multiplicity, size, and radial structure ofsuperclusters in the LambdaCDM concordance cosmology from z = 0 to z = 2.Superclusters are defined as clusters of clusters in our large-scalecosmological simulation. We find that superclusters are triaxial in shape; manyhave flattened since early times to become nearly two-dimensional structures atpresent, with a small fraction of filamentary systems. The size andmultiplicity functions are presented at different redshifts. Supercluster sizesextend to scales of ~ 100 - 200 Mpc/h. The supercluster multiplicity (richness)increases linearly with supercluster size. The density profile in superclustersis approximately isothermal (~ R^{-2}) and steepens on larger scales. Theseresults can be used as a new test of the current cosmology when compared withupcoming observations of large-scale surveys.Comment: 33 pages, 15 figures, accepted to ApJ; minor content changes, some figures removed to shorten pape