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I am quite fond of considering the information paradox of which the usual set up is an evaporating black hole that emits Hawking radiation. This set up or thought experiment is often considered in theoretical physics.

Now at the same time it is also true that astrophysicists like to study the radiative atmosphere or equivalently the accretion disk around the black hole (source). This leads to beautiful pictures or movies of simulations like on the following websites: 1 (youtube video), 2 (picture & article), 3 (another video).

Indeed, these are quite mesmerizing, though I do wonder, which is my question to you:

Is it fair to ignore the effects of the black hole accretion disk when considering the information paradox?

Or, perhaps inquired in a more closed-form: is there a consensus to the above question and if so, what is it? Another way of putting it (I think) is to phrase it as follows:

  1. the eternal black hole has no accretion disk (formally)
  2. the evaporating black hole (exerting hawking radiation) is considered with the information paradox
  3. the information paradox does not consider the eternal black hole and arguably does also not consider the accretion disk.

Question (alternative phrasing): Is it ever right or accurate to consider any black hole without accretion disk if it is not an eternal black hole?

My attempt to answer the question: I think the accretion disk is important for it determines the way matter may fall in to the black hole (through angular momentum constraints) and the accretion disk surely affects the particles i.e. Hawking radiation that carry the information. It is not clear to me if one may ever simplify the way that is addressed in the question above.

Looking forward to your answer!

P.S. this, this and this forum post seems to be related, though it does not provide (me) with an answer to my question.

jrobins
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Not all astrophysical black holes have accretion disks. Isolated stellar mass black holes without a partner should be, based on what we understand of black hole formation channels, more or less as common as black holes in binaries, but will typically not feature any significant accretion.

Astrophysicists like to study accretion onto black holes because this produces signals that can be observed. But this does not mean a black holes are like that.

Consequently it is perfectly ok to consider more isolated black holes for a thought experiment.

One caveat is that the cosmic background radiation provides a minimum to the expected accretion onto any black hole. At 2,7 K this is much much more intense than the Hawking radiation of a stellar mass black hole. So a thought experiment on black hole evaporation needs to wait for the universe to cool down before black holes can evaporate.

TimRias
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