Researchers at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) might have figured out how to explain dark matter halos around galaxies, according to a press release from the institute based on a study published in Physical Review D.

Dark matter, which is five times heavier than ordinary atoms, "gathers gravitationally" into halos, which attract atomic gas, forming galaxies. The "how" of dark matter clustering is known as the "halo bias problem," according to Kavlai IPMU.  

"Various studies have described the halo bias theoretically," said Teppei Okumura, a project researcher from Kavli IPMU. "However, none of them reproduced simulation results well. So, we extended prior studies motivated by a mathematical symmetry argument and examined if our extension works."

"The results of our study allow the distribution of dark matter halos to be more accurately predicted by properly taking into account higher-order terms missed in the literature," said lead investigator Shun Saito. "Our refined model has been already applied to actual data analysis in the BOSS project. This study certainly improves the measurement of the nature of dark energy or neutrino masses. Hence, it has led to a better understanding of the fundamental physics of the universe."

According to the institute, support for the study was provided by a Grant-in-Aid from the Japan Society for the Promotion of Science (JSPS) No. 25887012.