Abstract: Black holes are inherently chaotic objects. To truly understand this, one would need to compute the spectrum of black hole microstates and perform various spectral analyses—an extremely challenging task at present. However, thanks to semiclassical methods, early-time chaos can be observed in the probe sector of a black hole. Detecting signatures of late-time chaos in the probe sector, on the other hand, is more difficult, as naive 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 the black hole states, at least from the perspective of the two-point correlator.