In 2022, astronomers detected an absurdly bright and long-lasting gamma-ray burst, designated GRB 221009A and nicknamed "BOAT", the acronym in English for "Brightest of All Time", the brightest ever. The shower of photons was so ancient and so powerful that, in theory, it shouldn't have reached Earth.
However, the photons, including one with an energy of 300 TeV, did arrive. This fact constitutes an enigma for conventional physics, because according to existing models, such high-energy photons should have been absorbed by interaction with the cosmic infrared background during their journey of billions of years to our planet.
In a paper published in Physical Review Letters, two Italian physicists present a solution to this intriguing problem. The proposed explanation involves hypothetical particles from the cosmic dawn, that is, particles that existed in the most primordial phases of the universe.




