In the paper Enhanced control of light and sound trajectories with three-dimensional gradient index lenses - IOPscience the authors describe optical (and acoustical) black holes (in materials with a gradient refraction index):

optical.jpg

I'm curious: in such an optical black hole, shouldn't it be possible for radial light rays to escape (maybe similar to the Hawking radiation?)?

I assume the wave length would get longer as light escapes that way... so a black hole would (slowly) radiate "heat" (I guess it would have to, otherwise, the object would keep heating up)?

How fast would that be? Does anyone know how to calculate this :-)?

The reason I am interested in this is that I am fascinated by the theory that Hagen Kleinert, who have shown that a space-density tensor is equivalent to the spacetime tensor in GR:"A space with torsion and curvature can be generated from a Minkowski space via singular coordinate transformations and is completely equivalent to a crystal which has undergone plastic deformation being filled with dislocations and disclinations. Hagan Kleinert 1989"

So if the above theory is valid, then black holes in space could maybe be modeled just like optical black holes from the paper above.

In that case, then they should also radiate heat as in the Hawking radiation...

Best wishes,

Chantal