Brickwall, Normal Modes and Emerging Thermality
Black holes are inherently chaotic objects. To truly understand this, one must compute the spectrum of black hole microstates and perform various spectral analyses—an extremely challenging task at present. While early-time chaos can be observed, detecting signatures of late-time chaos is difficult, as naïve semiclassical quantization with ingoing boundary conditions leads to complex-valued quasinormal modes. In this talk, I will present an alternative approach to uncover hints of late-time chaos in the probe sector. Instead of imposing ingoing boundary conditions near the horizon, we will quantize the scalar field using Dirichlet boundary conditions—essentially following ’t Hooft’s brick wall model. I will also demonstrate how this brick wall state becomes indistinguishable from black hole states, at least from the perspective of the two-point correlator.

