A unit of information in black hole evaporation

Black holes evolve by evaporation of their event horizon. While this process is believed to be unitary, there is no consensus on the recovery of information in black hole entropy. A missing link is a unit of information in black hole evaporation. Distinct from Hawking radiation, we identify evaporation in entangled pairs by ${\mathbb{P}}^2$ topology of the event horizon consistent with the Bekenstein-Hawking entropy in a uniformly spaced horizon area, where $k_B$ denotes the Boltzmann constant. It derives by continuation of ${\mathbb{P}}^2$ in Rindler spacetime prior to gravitational collapse, subject to a tight correlation of the fundamental frequency of Quasi-Normal-Mode (QNM) ringing in gravitational and electromagnetic radiation. Information extraction from entangled pairs by detecting one over the surface spanned by three faces of a large cube carries a unit of information of $2\log 3$ upon including measurement of spin.