Analyses and measurements have shown anomalous behavior of ferrofluids in alternating and rotating magnetic fields, including flow reversals and negative magnetoviscosities as a function of magnetic field amplitude and frequency. These experiments measure the ferrofluid viscous torque on a rotating cylinder while varying the magnetic field amplitude and frequency, thereby confirming the strong ...

To investigate the formation mechanism of relativistic jets in active galactic nuclei and micro-quasars, we have developed a new general relativistic magnetohydrodynamic code in Kerr geometry. Here we report on the first numerical simulation of jet formation in a rapidly-rotating (a = 0.95) Kerr black hole magnetosphere. We study cases in which the Keplerian accretion disk is both co-rotating a...