Decoupling and non-decoupling dynamics of large D black holes

Understand

The limit of large number of dimensions localizes the gravitational field of a black hole in a well-defined region near the horizon.

• The perturbative dynamics of the black hole can then be characterized in terms of states in the near-horizon geometry.
• We investigate this by computing the spectrum of quasinormal modes of the Schwarzschild black hole in the 1/D expansion, which we find splits into two classes.
• Most modes are non-decoupled modes: non-normalizable states of the near-horizon geometry that straddle between the near-horizon zone and the asymptotic zone.