Physical objects approaching the Cauchy horizon of a fast spinning Kerr black hole

We solve the 2+1-dimensional Teukolsky equation numerically for the Weyl scalars ψ₀ and ψ₄ along a time-like geodesic intersecting with the Cauchy horizon of a rapidly rotating perturbed Kerr black hole. We find that both the amplitude and frequency of the Weyl scalars agree with the results of linear perturbation analysis. We then model a physical object by a simple damped harmonic oscillator, which is driven by an external force that mimics the tidal force experienced by the infalling object. We use this model to find the total deformation of the object at the Cauchy horizon, and the resonant effect when the driving force’s frequency matches the internal frequency of the oscillator that models the object.