Researchers Complete the First-Ever Trillion Particle Simulation of the Universe
​Image: Los Alamos NL

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Researchers Complete the First-Ever Trillion Particle Simulation of the Universe

But that’s barely just the start.

​Researchers have for the first time ever computed a complete trillion particle cosmological "dark sky" simulation. The result, a set of high-resolution "cyber images," is being made available to the public as a 55 terabyte data set. Said data provides a uniquely deep picture of the large-scale evolution of the universe, possibly offering clues into the nature of dark matter and dark energy. The research and resulting data is described in a new paper posted to arXiv.

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"In the past 40 years we have witnessed tremendous growth in the availability and utility of computational techniques and resources," said paper notes. "This has led to an equally astounding increase in the quality and accuracy of N-body simulations of cosmological structure formation, starting with [about] 1000 particles in early works to the current work with nine orders of magnitude more particles."

Particle-based simulations, in which large-scale cosmic features like gas clouds and stars (and the interactions between them) are represented by simple points, are a crucial tool for both connecting the realm of particle physics and cosmology and for studying the structural development of the universe since the Big Bang.

As can be seen in the composite image, the universe is composed of galaxies, filaments or tendrils connecting galaxies, and vast voids in between galaxies. The result is surprisingly uniform across space.

"The statistics of the distribution of these structures can be used in a variety of methods to constrain fundamental cosmological parameters," the paper continues. "For example, the number of objects in the Universe of a given mass, the mass function, is sensitive to cosmological parameters such as the matter density, the initial power spectrum of density fluctuations, and the dark energy equation of state."

Computing the mass function, however, is an enormous challenge owing to the complexity and scales involved. This is where simulations come in, though, as the paper notes, even models like this need to be repeated multiple times. The snapshot above is a mere ten-thousandth the scale of the actual simulation, which is itself a pale reflection of actual cosmological complexity. In other words, we're still just getting started.