Visible matter constitutes only 16% of the universe's total mass. Little is known about the nature of the rest of that mass, which referred to as dark matter. Even more surprising is the fact that the universe's total mass accounts for only 30% of its energy. The rest is dark energy, which is totally unknown but is responsible for the universe's accelerated expansion.
To find out more about dark matter and dark energy, astrophysicists use large-scale surveys of the universe or detailed studies of the properties of galaxies. But they can only interpret their observations by comparing them to predictions by theoretical models of dark matter and dark energy. But these simulations take tens of millions of computing hours on supercomputers.
Using the Joliot-Curie supercomputer, a team of astrophysicists from the French Alternative Energies and Atomic Energy Commission (CEA), Sorbonne Université, and Université Paris-Saclay, run a simulation of the evolution of cosmic structures from the first few moments after the Big Bang to the present day. They managed to describe the intergalactic regions, which represent 90% of the Universe's volume in unprecedented resolution. The findings were published in the recent issue of the journal Monthly Notices of the Royal Astronomical Society.
According to a report published Saturday on the CEA website, the simulation's high resolution in low density regions meant that it was able to describe cold gas accretion by galaxies and the formation of ultra-compact massive galaxies when the universe was only 2 to 3 billion years old. This step, which was only possible through a simulation on the supercomputer, helps establish the grounds to understand dark matter and dark energy.
The supercomputer offers a computing power of 22 petaflops, and the volume of numerical data processed exceeded 3TB at each step of the computation. The Joliot-Curie supercomputer was designed by the company Atos for GENCI (the French high-performance computing center).
