Nav: Home

The largest virtual Universe ever simulated

June 09, 2017

Researchers from the University of Zurich have simulated the formation of our entire Universe with a large supercomputer. A gigantic catalogue of about 25 billion virtual galaxies has been generated from 2 trillion digital particles. This catalogue is being used to calibrate the experiments on board the Euclid satellite, that will be launched in 2020 with the objective of investigating the nature of dark matter and dark energy.

Over a period of three years, a group of astrophysicists from the University of Zurich has developed and optimised a revolutionary code to describe with unprecedented accuracy the dynamics of dark matter and the formation of large-scale structures in the Universe. As Joachim Stadel, Douglas Potter and Romain Teyssier report in their recently published paper, the code (called PKDGRAV3) has been designed to use optimally the available memory and processing power of modern supercomputing architectures, such as the "Piz Daint" supercomputer of the Swiss National Computing Center (CSCS). The code was executed on this world-leading machine for only 80 hours, and generated a virtual universe of two trillion (i.e., two thousand billion or 2 x 1012) macro-particles representing the dark matter fluid, from which a catalogue of 25 billion virtual galaxies was extracted.

Studying the composition of the dark universe

Thanks to the high precision of their calculation, featuring a dark matter fluid evolving under its own gravity, the researchers have simulated the formation of small concentration of matter, called dark matter halos, in which we believe galaxies like the Milky Way form. The challenge of this simulation was to model galaxies as small as one tenth of the Milky Way, in a volume as large as our entire observable Universe. This was the requirement set by the European Euclid mission, whose main objective is to explore the dark side of the Universe.

Measuring subtle distortions

Indeed, about 95 percent of the Universe is dark. The cosmos consists of 23 percent of dark matter and 72 percent of dark energy. "The nature of dark energy remains one of the main unsolved puzzles in modern science," says Romain Teyssier, UZH professor for computational astrophysics. A puzzle that can be cracked only through indirect observation: When the Euclid satellite will capture the light of billions of galaxies in large areas of the sky, astronomers will measure very subtle distortions that arise from the deflection of light of these background galaxies by a foreground, invisible distribution of mass - dark matter. "That is comparable to the distortion of light by a somewhat uneven glass pane," says Joachim Stadel from the Institute for Computational Science of the UZH.

Optimizing observation strategies of the satellite

This new virtual galaxy catalogue will help optimize the observational strategy of the Euclid experiment and minimize various sources of error, before the satellite embarks on its six-year data collecting mission in 2020. "Euclid will perform a tomographic map of our Universe, tracing back in time more than 10-billion-year of evolution in the cosmos," Stadel says. From the Euclid data, researchers will obtain new information on the nature of this mysterious dark energy, but also hope to discover new physics beyond the standard model, such as a modified version of general relativity or a new type of particle.

University of Zurich

Related Dark Matter Articles:

Physicists have found a way to 'hear' dark matter
Physicists at Stockholm University and the Max Planck Institute for Physics have turned to plasmas in a proposal that could revolutionise the search for the elusive dark matter.
Cesium vapor aids in the search for dark matter
Physicists at Mainz University manage to further narrow down range of the search for dark matter
New hunt for dark matter
Dark matter is only known by its effect on massive astronomical bodies, but has yet to be directly observed or even identified.
Tracking down dark matter
Over time, scientists have developed different theories to explain exactly what the mysterious dark matter might be made of.
A new candidate for dark matter and a way to detect it
Two theoretical physicists at UC Davis have a new candidate for dark matter and a possible way to detect it.
More Dark Matter News and Dark Matter Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...