Cosmic rays from heart of darkness?

摘要

The nature of dark matter and the source of ultra-high energy cosmic rays are two of the biggest unsolved mysteries in physics. A mammoth instrument nearing completion in Argentina could soon tell us whether the two questions are linked.rnAccording to standard physics, cosmic rays with energies greater than about 5 x 10~(19) electronvolts collide with photons of the cosmic microwave background left over from the big bang and so lose energy over long distances. This puts a limit on how energetic they are when they reach Earth, called the Greisen-Zatsepin-Kuzmin(GZK) cut-off.