Semiclassical effects on the inner (Cauchy) horizon of rotating black holes

Semiclassical gravity leads to well-known important effects outside black holes such as the emission of quantum (Hawking) radiation. Recently, interesting semiclassical gravity effects inside black holes have also been unveiled. In this talk, we will present some of these effects, including the abrupt expansion, contraction and twisting that observers may experience when approaching the inner Cauchy horizon of rotating black holes (Kerr and Kerr-de Sitter), as well as the irregularity of this Cauchy horizon, with consequences for Penrose’s strong Cosmic Censorship hypothesis and the predictability of Einstein’s equations of General Relativity.