Exact results for Kerr black holes: shadow areas and perimeters, capture of slow particles, and escape from near extremal horizons
We give exact results for several observables of Kerr black holes that have so far been computed numerically, by fits, or only at isolated parameter values. (i) The area of the shadow seen by an equatorial observer, for every spin, in complete elliptic integrals, together with its small-spin series and its near-extrema...