Fast radio bursts (FRBs) are extremely bright, short-lived flashes of radio waves that originate from distant parts of the universe, sometimes billions of light-years away. These bursts travel through space and interact with the matter they pass through, which can affect how we detect them on Earth. Scientists are increasingly using FRBs as tools to study the distribution of ordinary matter in the universe, known as baryons. A new study published in Nature Astronomy reveals that FRBs can help researchers differentiate between the effects of galactic processes and the mysterious forces of dark matter and dark energy. Galactic feedback refers to processes like the expulsion of hot gas from supermassive black holes or the energy released by exploding stars. These events can influence how matter is distributed in the universe, making it less clumpy. The effects of these processes can be similar to those predicted by theories involving dark matter and dark energy, making it difficult for scientists to tell them apart. This challenge has limited progress in understanding the true nature of dark matter and dark energy, as well as the mass of neutrinos, which are subatomic particles that are notoriously hard to detect. In the new study, researchers analyzed data from approximately 100 FRBs to examine how galactic feedback affects the distribution of matter in the large-scale structure of the universe. Their findings suggest that galactic feedback does indeed smooth out the distribution of matter, reducing its clumpiness. However, the degree of this smoothing is less than what had been previously estimated by other major surveys, such as the eROSITA X-ray telescope and the Atacama Cosmology Telescope, which operated until 2022. The study’s authors argue that FRB data can provide valuable insights into how cosmic structures are suppressed, comparable to the results from X-ray and microwave surveys. While galactic feedback has a noticeable impact on matter distribution, its influence is not as strong as earlier estimates suggested. Kritti Sharma, a graduate student at Caltech and lead author of the study, emphasizes that FRBs are a powerful tool for mapping the distribution of matter in the universe. Their use could significantly enhance efforts to study dark matter, dark energy, and the mass of neutrinos, offering a new perspective on some of the most fundamental questions in cosmology.