B Paradox about black hole evaporation

[Tomas Vencl]

That quantity is not limited to $c$; it increases without bound as $r = 0$ is approached. So it cannot be interpreted as a "speed".

If you are fine with that, then I think the answer is that $dr / d\tau = c$ when the true event horizon is crossed, but I have not done the math to confirm that.

Thank you. (I used "speed" because it corresponds to Newtonian escape velocity, But I do not need to interpret it as "speed",just $dr / d\tau$ is ok.)

 

[otennert]

Found the paper by Ashtekar and Bojowald 2005. It is not very technical but has some references that surely need to be read in addition, but summarizes a lot of issues with the "traditional" semi-classical approach instigated by Hawking on BH evaporation.

 

[PeterDonis]

Found the paper by Ashtekar and Bojowald 2005.

Arxiv link is here since the iopscience paper is behind a paywall:

https://arxiv.org/abs/gr-qc/0504029

 

[PeterDonis]

this is based on the assumption that the final naked singularity is spacelike

The singularity isn't naked since it's behind a horizon, but it is spacelike, yes, like the one for an eternal Schwarzschild black hole.

to me it is not really clear that this is the case. It is not even clear to me that a final singularity exists at all.

Yes, that's an open question. But this particular thread is discussing that model, since that's the setting for the OP's scenario.

 

[PeterDonis]

The discussion has evolved

You're the only one who is trying to do that. If you want to discuss the more general questions you are raising, please start a separate thread.

 

[PeterDonis]

The OP question has been answered, and this thread is closed.