Signatures of Magnetized Large Scale Structure in Ultra-High Energy Cosmic Rays

We investigate the impact of a structured universe in the multi-pole moments, auto-correlation function, and cluster statistics of cosmic rays above 10^19 eV. We compare structured and uniform source distributions with and without magnetic fields obtained from a cosmological simulation. We find that current data marginally favor structured source distributions and magnetic fields reaching a few micro Gauss in galaxy clusters but below 0.1 micro Gauss in our local extragalactic neighborhood. A pronounced GZK cutoff is also predicted in this scenario. Future experiments will make the degree scale auto-correlation function a sensitive probe of micro Gauss fields surrounding the sources.