Universe generator

This tool uses an emulator built using twinLab and trained on HMcode predictions, which is then combined with a log-normal field model to produce realisations of the matter distribution in the Universe. This is a quick method for generating mock universes, which would otherwise require expensive $N$-body simulations to create. Areas of higher matter density are shown with brighter colours. The region of the Universe shown is 500 megaparsecs across and one megaparsec deep, which would contain approximately 250,000 galaxies and would take light more than 1.5 billion years to cross. Galaxies are clustered into huge superclusters, which are joined by filaments and separated by voids.

You can change the density of both dark and normal (baryonic) matter, the Hubble parameter, the primordial inflationary spectral index, and the dark-energy equation-of-state. The other default values (including the amplitude of the primordial spectrum) are the best-fitting values from the Planck (2018) data release.