Motion of charged particles in a NUTty Einstein-Maxwell spacetime and   causality violation
  We investigate the motion of electrically charged test particles in spacetimes with closed timelike curves, a subset of the black hole or wormhole Reissner-Nordstr\"om-NUT spacetimes without periodic identification of time. We show that, while in the wormhole case there are closed worldlines inside a potential well, the wordlines of initially distant charged observers moving under the action of the Lorentz force can never close or self-intersect. This means that for these observers causality is preserved, which is an instance of our weak chronology protection criterion. 
G\'erard Cl\'ement and Mourad Guenouche
gr-qc hep-th