Large-Scale Structure

What is Large-Scale Structure?

Galaxies are not randomly distributed throughout the cosmos, but preferentially reside in associations called groups and clusters. Groups and clusters themselves are not isolated, but are connected and arranged in a non-trivial manner by features of large-scale structure, including filaments, walls and superclusters. Additionally, vast voids fill over half of the universe's volume, containing very few galaxies. This "cosmic web" must be understood in order to test cosmology and enable closer study of how a galaxy's evolution is influenced by its environment.

A cube of side 160 Mpc/h at 0.06 < z < 1.12, encompassing the scale of homogeneity. The smoothed galaxy distribution clearly shows the filamentary network, and a large void.

Recent and Current Research

Groups, Filaments and Voids
Modern galaxy catalogues contain vast amounts of data. Ideally, the burden of interpreting this data to locate cosmic superstructures should be borne by algorithms run on computers. MSPM is one such algorithm that has been implemented on real data to coarse-grain the galaxy distribution. Filaments and voids have been identified from this coarse-grained representation.