Most comprehensive map of the universe created

Astrophysicists have created a 3D map of the universe that spans nearly two billion light years and is the most complete picture of our cosmic neighbourhood to date.
The spherical map of galaxy super-clusters will lead to a greater understanding of how matter is distributed in the universe and provide key insights into dark matter, one of physics' greatest mysteries.
"The galaxy distribution isn't uniform and has no pattern. It has peaks and valleys much like a mountain range. This is what we expect if the large-scale structure originates from quantum fluctuations in the early universe," said Professor Mike Hudson of the Department of Physics and Astronomy at the University of Waterloo.

Knowing the location and motion of matter in the universe will help astrophysicists predict the universe's expansion and identify where and how much dark matter exists.
Scientists have observed that galaxies move differently because the universe's expansion is not even.
These differences are called peculiar velocities. Our own Milky Way galaxy and its neighbour Andromeda are moving with a speed of 2 million kilometres per hour, researchers said.

Previous models haven't fully accounted for this observed motion. Hudson and his team are interested in discovering what structures are responsible for the peculiar velocities.
These deviations in the motion of galaxies are a valuable tool to determine the distribution of matter and dark matter on the largest scales.

Dark matter accounts for a large majority of the mass content in the universe. It is a hypothesised form of matter particle that does not reflect or emit light and as a result it can't be seen or measured directly.
The existence and properties of dark matter can only be inferred indirectly through its gravitational effects on visible matter and light.
"A better understanding of dark matter is central to understanding the formation of galaxies and the structures they live in, such as galaxy clusters, super-clusters and voids," said Hudson.
The research appears in the journal Monthly Notices of the Royal Astronomical Society.