HET Journal club: Aron Jansen

Speaker: Aron Jansen

Title: Scalar Instabilities in AdS and dS

Abstract: This talk will consist of two parts, relating to the weak and strong cosmic censorship conjectures respectively. In the first part, I will show a very simple QCD inspired holographic model that has surprisingly rich dynamical behavior. It has a dynamical instability that can result in a runaway solution with ever increasing horizon area and no end point. It is a rather generic behavior for Einstein-scalar theories with a scalar potential that is "steep enough". This seems to violate weak cosmic censorship and puts limits on sensible bottom-up models in holography. 

The second part tests the strong cosmic censorship conjecture for a Reissner-Nordstrom black hole in 4-dimensional de Sitter spacetime. It turns out that the conjecture depends on its quasinormal modes. We compute them and argue that the conjecture is violated near extremality.