Black holes have more states than those giving the Bekenstein-Hawking entropy: a simple argument

Abstract

It is often assumed that the maximum number of independent states a black hole may contain is \(N_{BH}=e^{S_{BH}}\), where \(S_{BH}=A/4\) is the Bekenstein-Hawking entropy and \(A\) the horizon area in Planck units. I present a simple and straightforward argument showing that the number of states that can be distinguished by local observers inside the hole must be greater than this number.