From bricks to quasinormal modes: A new perspective on black hole entropy

Understand

Calculations of black hole entropy based on the counting of modes of a quantum field propagating in a Schwarzschild background need to be regularized in the vicinity of the horizon.

• To obtain the Bekenstein-Hawking result the short distance cut-off needs to be fixed by hand.
• In this note we give an argument for obtaining this cut-off in a natural fashion.
• We do this by modelling the black hole by its set of quasinormal modes.