1:30 pm MCP 201
Surprising properties of cold black holes.
In recent years we have learned that near-extremal black holes are a great window into quantum gravity — one needs to go beyond the saddle-point approximation to consistently describe their thermodynamics. I will argue that they become great probes of new physics already at higher temperatures. We will start with a discussion of how their geometry depends on boundary conditions or sources far away in AdS spacetimes. Then we will show that in asymptotically flat spacetimes this effect goes away. However, they become very sensitive to higher-derivative corrections (coming, for example, from electron loops in QED). These corrections generically lead to large tidal forces at the horizon. In particular, this indicates that the effective field theory breaks down in a regime in which the curvature computed in the two-derivative theory is very low. Finally, we will go back to even lower temperatures and discuss dynamical counterparts of these effects.