Signature of nonuniform area quantization on black hole echoes

A classical black hole is characterized by a horizon that absorbs the radiation of all frequencies incident on it. The perturbation of these black holes is well understood via exponentially damped sinusoids known as quasinormal modes. Any departure from such classical behavior near the horizon may induce significant modifications in the late-time evolution of the perturbation leading to so-called gravitational wave echoes. This work considers the effect of black hole area quantization on the formation of gravitational wave echoes. We investigate how the resulting echo waveform may depend on various model parameters. Our study opens up a new window to distinguish different models of area quantization using future gravitational wave observations and provides a novel probe to study the near-horizon physics.