Séminaire / Seminar GReCO |
| « Black hole instabilities and the formation of singularities in general relativity » |
|
Pau Figueras |
| Black holes play a central role in our understanding of general relativity, the currently accepted classical theory of gravity. The recent discovery of gravitational waves by the Ligo-Virgo collaboration confirmed their existence in Nature. But the importance of four dimensional black holes to describe some of the observed compact dark objects in the Universe hinges on their dynamical stability under small perturbations. In recent years, motivated by more fundamental theories of gravity such as string theory, there has been a lot of interest in the community to study black holes in spacetimes with more than four spacetime dimensions. In this talk I will show that in dimensions higher than four, black holes can be dynamically unstable. Furthermore, I will present results of numerical simulations of these instabilities in full non-linear regime that suggest that unstable horizons develop a fractal structure that leads to a naked singularity in finite time. Moreover, I will argue that the mechanism behind these instabilities is universal. These results provide evidence that the weak cosmic censorship conjecture, which is the greatest unsolved problem in general relativity, is false in spacetimes with more than four dimensions. |
|
mardi 18 octobre 2016 - 14:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |