  Observed events of ultra-high energy cosmic rays may indicate a hard
component for the energy spectrum of their flux, which might have origin in the
decay of long-lived vortons presumably condensed in the galactic halo. To be
consistent with the needed present density, vortons may have been formed during
the breaking of an abelian symmetry contained in a large GUT group like E6 and
a part of them could have survived the destabilization caused by the
electroweak transition.
