Classical Aspects of Black Hole Interiors

We will discuss the geometry behind the horizon of various asymptotically AdS black holes when the boundary CFT is deformed by a scalar operator. The dynamics of classical GR in the region inside the black hole turns out to be rather intricate, with even fractal like behavior emerging in some situations. We will see that, generically, in the presence of a scalar deformation, Cauchy horizons are replaced by a spacelike singularity. This motivates a notion of 'holographic' cosmic censorship. This talk is based on 2004.01192, 2006.10056 and 2008.12786.