One promising hypothesis for this uneven distribution of visible matter is that, at the time of the Big Bang, there were already quantum fluctuations, or random, temporary changes in energy, in the tiny, primordial universe, Shirasaki said. ?
When the universe expanded, these fluctuations would have expanded, too, with denser points stretching into regions of greater density than their surroundings.The researchers developed a reconstruction method to do just that.So they used NAOJ's ATERUI II supercomputer to create 4,000 versions of the universe, all with slightly different initial density fluctuations.
The researchers allowed these virtual universes to undergo their own virtual inflations and then applied the reconstruction method to them, to see if it could get them back to their original starting points.
"We find that a reconstruction method can reduce the gravitational effects on observed galaxy distributions, allowing us to extract the information of initial conditions of our universe in an efficient way," Shirasaki said