Internal Structure of Black Holes

Abstract.

Gravitational collapse to a black hole leaves a decaying wake of gravitational waves. Some of those waves are absorbed into the hole and have dramatic effects on the geometry near the inner (Cauchy) horizon because of a diverging blueshift. Determining the inner structure of the hole is really an evolutionary problem with precisely known initial data. The evolution can in principle be followed to within Planck distances of the singularity at the inner horizon, using only well-established physical laws (the Einstein field equations). This lecture reviews recent progress in this area, highlighting outstanding problems and gaps.