Holes in general relativity

Black holes in general relativity

What is going on (as of August 2008) at the interface between theoretical general relativity, stringinspired models, and observational astrophysics? Quite a lot. In this mini-survey I will make a personal choice and focus on four specific questions: Do black holes “exist”? (For selected values of the word “exist”.) Is black hole formation and evaporation unitary? Can one mimic a black hole to a...

Formation of Supermassive Black Holes: Simulations in General Relativity

There is compelling evidence that supermassive black holes exist. Yet the origin of these objects, or their seeds, is still unknown. We discuss several plausible scenarios for forming the seeds of supermassive black holes. These include the catastrophic collapse of supermassive stars, the collapse of relativistic clusters of collisionless particles or stars, the gravothermal evolution of dense ...

Entropy of Constant Curvature Black Holes in General Relativity

We consider the thermodynamic properties of the constant curvature black hole solution recently found by Bañados. We show that it is possible to compute the entropy and the quasilocal thermodynamics of the spacetime using the Einstein-Hilbert action of General Relativity. The constant curvature black hole has some unusual properties which have not been seen in other black hole spacetimes. The e...

Black Holes and the Penrose Inequality in General Relativity

In a paper [23] in 1973, R. Penrose made a physical argument that the total mass of a spacetime which contains black holes with event horizons of total area A should be at least √ A/16π. An important special case of this physical statement translates into a very beautiful mathematical inequality in Riemannian geometry known as the Riemannian Penrose inequality. One particularly geometric aspect...

General Relativity and Compact Objects – Neutron Stars and Black Holes