کارکره

thumb|right|300px|At the ergospheres (shown here in violet for the outer and red for the inner one), the temporal metric coefficient gtt becomes negative, i.e., acts like a purely spatial metric component. Consequently, timelike or lightlike worldlines within this region must co-rotate with the inner mass. Kerr–Newman metric#Alternative .28Kerr.E2.80.93Schild.29 formulation|Cartesian projection, equatorial perspective.