The Network Behind the Cosmic Web
  The concept of the cosmic web, viewing the Universe as a set of discrete galaxies held together by gravity, is deeply engrained in cosmology. Yet, little is known about the most effective construction and the characteristics of the underlying network. Here we explore seven network construction algorithms that use various galaxy properties, from their location, to their size and relative velocity, to assign a network to galaxy distributions provided by both simulations and observations. We find that a model relying only on spatial proximity offers the best correlations between the physical characteristics of the connected galaxies. We show that the properties of the networks generated from simulations and observations are identical, unveiling a deep universality of the cosmic web. 
B. C. Coutinho, Sungryong Hong, Kim Albrecht, Arjun Dey,   Albert-L\'aszl\'o Barab\'asi, Paul Torrey, Mark Vogelsberger and ...
astro-ph.CO