The unit of measurement used is the light-year (distance traveled by light in one Julian year; approximately 9.46 trillion kilometres).
This list includes superclusters, galaxy filaments and large quasar groups (LQGs).
This list refers only to coupling of matter with defined limits, and not the coupling of matter in general (such as, for example, the cosmic microwave background, which fills the entire universe).
Voids are immense spaces between galaxy filaments and other large-scale structures.
They are theorized to be caused by quantum fluctuations during the early formation of the universe.