New research using observations from dwarf galaxies has set a lower limit on the mass of dark matter particles. But the results contradict findings from several previous experiments, which observed dark matter particles with masses below this threshold.
Dark matter is an invisible substance found throughout the universe that doesn’t emit any light. Scientists know that if dark matter exists, then so does anti-dark matter, and putting the two together will cause them to annihilate each other and produce gamma radiation.
“We are looking for this byproduct of the annihilation,” said physicist Savvas Koushiappas of Brown University in Providence, Rhode Island, who co-authored one of the papers, which will both be published Dec. 1 in Physical Review Letters.