Tidal effects on magnetic gyration of a charged particle in Fermi coordinates

We examine gyration motion of a charged particle viewed from a reference observer falling along Z axis into Schwarzschild black hole. The magnetic field is assumed to be constant and uniform along Z axis. The motion far from the gravitational source is circular in X-Y plane. Fate of the circular orbit is calculated as the reference observer approaches the black hole. The circular orbit is eventually disrupted due to tidal force. The final plunging velocity increases in the non-relativistic treatment. On the other hand, the plunging velocity decreases, if initial circular velocity exceeds a critical value ∼ 0.7c. This toy model suggests that disruption of rapidly rotating star may be quite different from that of non-relativistic star due to velocity-dependent tidal force. We also found that the collapse of the orbit after the disruption is slow in general so that the particle subsequently escapes outside of valid Fermi coordinate system. PACS numbers: 04.20.Cv, 97.60.Jd, 97.60.Lf † Email: [email protected] ‡ Email: [email protected] Tidal effects on magnetic gyration 2