A new simulation maps the first seconds after the Big Bang, focusing on what scientists call the intergalactic medium, or the gas and dust between galaxies.
A team led by researchers from the Institute for Astrophysics of the Canary Islands (IAC) used machine learning, a type of algorithm that trains a computer to recognize patterns, to complete 100,000 hours of computation. The algorithm for this project is called Hydro-BAM.
This new work allowed researchers to chart phenomena such as dark matter, energized gas, neutral hydrogen and other cosmic constituents that are essential to understanding the structure of our universe, IAC officials said in a May 20 statement (opens in new tab).
Related: The History of the Universe: Big Bang to Date in 10 Easy Steps
“The research has also made it possible to reproduce the so-called ‘Lyman alpha forests’ with high precision,” they added. This is a specific pattern of lines in a spectrum (light signature) of galaxies and similar objects, formed when clouds of hydrogen gas in the path absorb the galactic light.
“These ‘virtual universes’ serve as testbeds for studying cosmology,” the researchers added. “However, the simulations are very computationally intensive and the current computer facilities only allow this [us] to explore small cosmic volumes.”
Hydro-BAM was designed to incorporate probability, machine learning and cosmology, i.e. the history of the universe. “This algorithm made it possible to obtain very accurate predictions in just a few tens of seconds,” the researchers said.
By mapping the absorption lines in the galactic spectra, the team was able to pinpoint where the clouds of hydrogen gas are located. Location is an indicator of distance as the universe is constantly expanding. The clouds also provide clues as to what is contained within the intergalactic medium of gas and dust.
“The breakthrough came when we understood that the connections between the amounts of intergalactic gas, dark matter, and neutral hydrogen that we were trying to model are well organized hierarchically,” says Francesco Sinigaglia, a PhD student at La Laguna University in Spain. the IAC and the University of Padua in Italy and lead author of the research, said in the statement.
The most recent study on the research was published in The Astrophysical Journal in March, and a related study was published in the same journal in November 2021.