Kaluza–Klein theory, AdS/CFT correspondence and black hole entropy

Abstract

The asymptotic symmetries of the near-horizon geometry of a lifted (near-extremal) Reissner–Nordstrom black hole, obtained by inverting the Kaluza–Klein reduction, explain the deviation of the Bekenstein–Hawking entropy from extremality. We point out the fact that the extra dimension allows us to justify the use of a Virasoro mode decomposition along the time-like boundary of the near-horizon geometry, AdS2 × Sn, of the lower-dimensional (Reissner–Nordstrom) spacetime.