February 17: Mehrdad Mirbabayi (IAS)
Time: 2 pm
Place: DRL 2N36
Stars and black holes in massive gravity
I will consider spherically symmetric solutions in an asymptotically flat universe with a massive graviton, and argue that: (a) For small graviton mass ($m$) Einstein gravity is recovered at small radii, as Vainshtein anticipated. (b) Static black holes, however, are singular at horizon, no matter how small is the graviton mass. (c) Analogously, static charged black holes have a horizon singularity in massive electrodynamics. In reality, they loose their electric field and discharge. (d) Black holes in massive gravity must also be time-dependent. Now they loose mass and gradually disappear. (e) The disappearance rate of a black hole with radius $r_g$ scales as $m^2 r_g$. Therefore, in the limit $m\to 0$ one recovers Einstein gravity.