large scale structure

The large scale structure of the universe, also known as the cosmic web, is the overall placement of mass in the volume of the universe. Clusters are within superclusters, in turn, in surfaces (sheets, walls) and strings (galaxy filaments) separated by large voids.

A picture of the general structure began with the 1989 discovery of the Great Wall, a sheet of galaxies, part of growing evidence that galaxy clusters are not evenly distributed. Currently, cosmological simulations aim to produce a structure similar to that observed, i.e., show a similar large scale structure. Presumed factors include entropy, pressure, density, and gravitational potential.

Mapping of distant galaxies reveal aspects of the large scale structure, as do various kinds of intensity mapping, studies of Lyman-alpha forests, and studies of the cosmic microwave background (CMB), e.g., of the Sunyaev-Zel'dovich effect

The term large scale structure is also frequently used to refer to one of these large elements, e.g., to a supercluster or galaxy filament.