Open access
Oct 2026
Exploring cosmic rays from gravity-limited acceleration at supermassive black holes
We show that horizon-scale magnetic fields around supermassive black holes (SMBHs), only limited by gravity, yield a universal, model-independent ceiling on electromagnetic energy density. For rotating SMBHs, this field enables particle acceleration up to $\sim\!10^{27}$\,eV set solely by fundamental constants. We iden...
E. Manao, E. Resconi, F. Rieger et al.
· Physical Review Letters · 0 citations