Before revision: The Greisen–Zatsepin–Kuzmin limit (GZK limit ) is a theoretical upper limit on the energy of cosmic ray protons traveling from other galaxies through the intergalactic medium to our galaxy.
After revision: or GZK cutoffThe Greisen–Zatsepin–Kuzmin limit (GZK limit ) is a theoretical upper limit on the energy of cosmic ray protons traveling from other galaxies through the intergalactic medium to our galaxy.