Black hole critical phenomena without black holes

Black Hole Critical Phenomena Without Black Holes

Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical phenomena, discuss some recent results, and describe a model which demonstrates similar...

Black holes and black hole thermodynamics without event horizons

Black Hole thermodynamics without a black hole?

In the present paper we consider, using our earlier results, the process of quantum gravitational collapse and argue that there exists the final quantum state when the collapse stops. This state, which can be called the “no-memory state”, reminds the final “no-hair state” of the classical gravitational collapse. Translating the “no-memory state” into classical language we construct the classica...

Black hole excision for dynamic black holes

We extend the previous work on 3D black hole excision to the case of distorted black holes, with a variety of dynamic gauge conditions that respond naturally to the spacetime dynamics. We show that in evolutions of highly distorted, rotating black holes, the combination of excision and the gauge conditions we use is able to drive the coordinates to a frame in which the system looks almost stati...

Black Holes Without Singularities

We study the properties of a completely integrable deformation of the CGHS dilaton gravity model in two dimensions. The solution is shown to represent a singularity free black hole that at large distances asymptoticaly joins to the CGHS solution. One of the fundamental unsolved problems in theoretical physics is the unification of quantum theory and gravity. One of the reason why this is so dif...