UHECRs from the Radio Lobes of AGNs

We report a stochastic mechanism of particle acceleration from first principles in an environment having properties like those of Radio Lobes in AGNs. We show that energies $\sim 10^{20}$ eV are reached in $\sim 10^6$ years for protons. Our results reopen the question regarding the nature of the high-energy cutoff in the observed spectrum: whether it is due solely to propagation effects, or whether it is also affected by the maximum energy permitted by the acceleration process itself.