Electromagnetic Energy Extraction in Kerr Black Holes through Frame-Dragging Magnetospheres

It is argued that the zero-angular-momentum-observers (ZAMOs) circulating with the frame-dragging-angular-velocity $\omega$ plays a leading part in energy extraction. When the condition $\Omega_{\rm F}0$), whereas the inner domain ${D}_{\rm (in)}$ inside spins backward ($\Omega_{\rm ZF}