Dark matter is one of those things we know is there but can’t see. Trying to map it would be like trying to map the air – we know there are currents and eddies all around us, but without special instruments we can’t see them. Dark matter is similar. We know dark matter is out there because it pulls on things, just like we can see evidence of air currents by seeing leaves move in the breeze. Researchers at the UCLA Department of Physics and Astronomy are using their U.S. National Science Foundation ACCESS allocations on Anvil, Purdue’s Rosen Center for Advanced Computing (RCAC) flagship supercomputer, to run simulations so they can better understand how dark matter works.

Claire Williams, a Ph.D. student at UCLA, is part of the Supersonic Project, a collaboration that studies how stream velocity and dark matter affected galaxy formation in the early universe. Her work focuses on stream velocity and has been published in The Astrophysical Journal

“So our specific studies are trying to gain a more precise understanding of the process by including effects that previously nobody included,” said Williams. “People already had dark matter, they already had gas, but they were missing the stream velocity. It has been largely ignored because it is challenging to get right in simulations. But neglecting the fact that material was moving past the dark matter at five times the speed of sound inevitably leads to a different result. What our group has done is to run simulations that correctly include the relative motion of dark matter and ordinary matter at early times in the universe.”

Using data from the James Webb Space Telescope (JWST), Williams’ research group is running Anvil simulations of space that are equivalent in size to the combined Milky Way and Andromeda galaxies. Simulations on such a massive scale truly benefit from resources like Anvil. High-performance computing (HPC) resources are also essential once all the simulations are complete, because the simulations generate mountains of data that need to be analyzed. With an ACCESS allocation, it’s easy for researchers to use HPC resources at any step of their research project that could benefit from them.

To read more about this fascinating research, you can find the full story here: Anvil used to study dark matter and early universe formation.

If you’re a researcher who could benefit from HPC resources, you can get started with ACCESS here.

Resource Provider Institution(s): Purdue’s Rosen Center for Advanced Computing (RCAC)
Resources Used: Anvil
Affiliations: UCLA
Funding Agency: NSF 
Grant or Allocation Number(s): PHY250057

The science story featured here was enabled by the U.S. National Science Foundation’s ACCESS program, which is supported by National Science Foundation grants #2138259, #2138286, #2138307, #2137603, and #2138296.