Gravity distorts galaxies’ light — a process called gravitational lensing — and also slightly aligns the galaxies physically, resulting in additional gravitational lensing light signals that contaminate the true data. “The self-calibration method is something others proposed about 10 years ago; many thought it was just a theoretical method and moved away from it,” Ishak-Boushaki said. “It can help us map the distribution of dark matter and discover information about the structure of the universe. In their study, the research team used the self-calibration method to extract the nuisance signals from a type of alignment called intrinsic shape-gravitational shear, which is the most critical component. These are very important questions.”Impact on CosmologySeveral large scientific surveys aimed at better understanding the universe are in the works, and they will gather gravitational lensing data.