christmas became an official us holiday on december 26, 1776.
when did christmas become an official us holiday?
december 26, 1776
Na
Na
section::::nhm of extremal kerr black holes.





























the metric of extremal kerr black hole (formula_5) in boyer–lindquist coordinates can be written in the following two enlightening forms,





























where





























taking the near-horizon limit





























and omitting the tildes, one obtains the near-horizon metric (this is also called "extremal kerr throat" )





























section::::nhm of extremal kerr–newman black holes.





























extremal kerr–newman black holes (formula_11) are described by the metric





























where





























taking the near-horizon transformation





























and omitting the tildes, one obtains the nhm





























section::::nhms of generic black holes.
near-horizon metric