Black Holes & Firewalls: Recent Papers

[Haelfix]

I think he means that it would be inconsistent to write down the state vector as |Alive> + |Dead> as seen by an infalling observer which the equivalence principle would naively seems to suggest. Instead it would be some horrible mix with all the scrambled degrees of freedom from the black hole and there is no quantum mechanical framework that would accurately predict the state vector for that type of experiment..

In a sense, a firewall is the complete excision of region II in a Kruskal diagram, the singularity is essentially moved right to the horizon..

 

[Demystifier]

A quote from the conclusion of the Marolf-and-Polchinski PRL paper:
"One may feel that all of these arguments are indirect,
based on logical deduction from general principles rather
than a concrete realization of quantum gravity in the bulk;
the same can be said of most of the literature arguing for or
against the firewall. Thus, we believe that a central lesson
is that, while gauge-gravity duality is a powerful tool, it is
not as complete a description as might have been believed,
and there is a gap to fill in the current understanding of
quantum gravity, even in anti–de Sitter spacetime."

 

[PAllen]

Can anyone explain more about the content of this article? It seems to be an attempt to water down Marolf and Polchinski's recent paper http://arxiv.org/abs/1307.4706 for nonspecialists, but it doesn't seem watered down enough for me to understand. He loses me in the first paragraph:



Why would we expect to have a calculation that could predict the outcome of this measurement? Don't we expect it to be random?

Note that the second of the two links I posted above claims to refute this paper's conclusions.

 

[MTd2]

Note that the second of the two links I posted above claims to refute this paper's conclusions.

But as Haelfix said, it is dificult to figure out what is general or not. For exmple, they suppose the existence of a superobserver which can both see inside or outside the black hole. They state it in the conclusion. And in the introduction, they say they give up background independence for local operators.

With this thing, they can build state dependent Operators, such that one inside and other outside can commute.

I am not sure if this is a fair approximation for the problem in hand. It sounds like there is a kind of operator that somehow is godlike and can trample GR.

 

[atyy]

But as Haelfix said, it is dificult to figure out what is general or not. For exmple, they suppose the existence of a superobserver which can both see inside or outside the black hole. They state it in the conclusion. And in the introduction, they say they give up background independence for local operators.

With this thing, they can build state dependent Operators, such that one inside and other outside can commute.

I am not sure if this is a fair approximation for the problem in hand. It sounds like there is a kind of operator that somehow is godlike and can trample GR.

I don't think that's the generalizability issue of the Papadodimas and Raju papers. In their first paper, their construction was used on the eternal AdS black hole. The ER=EPR paper was also similarly special.

There should be a godlike view of the situation, which is different from the low energy experiments the infalling observer can do. That seems reasonable. The surprising thing is that the infalling operators may have to be state dependent. In Mathur's viewpoint, he has long proposed the the fuzzball structure shouldn't be seen by "macroscopic" observer. I think the technical questions are how to construct the interaction of the macroscopic observer, and also what is the fuzzball picture for an evaporating black hole?

Also, couldn't giving up background independence for local operators be more background independent in the GR sense? If the local operators depend on the background, it is analogous to how in GR you cannot specifiy the matter configuration independently of the background.

 

[audioloop]

I think he means that it would be inconsistent to write down the state vector as |Alive> + |Dead> as seen by an infalling observer which the equivalence principle would naively seems to suggest. Instead it would be some horrible mix with all the scrambled degrees of freedom from the black hole and there is no quantum mechanical framework that would accurately predict the state vector for that type of experiment...

fully concur.




.

 

[audioloop]

Maldacena-Susskind, any entangled state is just an Einstein-Rosen brigde, Locality saved then.and:

http://physics.aps.org/articles/v6/115
"As Maldacena and Susskind recently explained, nonlocality issues could also be reconciled [5]. They postulate that thermal Hawking radiation, as it is emitted from the black hole, remains connected to the inside of the black hole by microscopic wormholes. These wormholes allow signals from the outside observer to immediately pop up inside the black hole, but not vice versa. While Marolf and Polchinski argue against this scenario, they admit that it may be consistent if one allows for a state-dependent identification between observers. And as we’ve seen, this state-dependent identification seems to be inevitable if one wants to avoid firewalls via complementarity anyway.

It is my view that state dependence is much easier to accept than the ad hoc introduction of firewalls. But the work of Marolf and Polchinski delivers a key message: one will have to accept either state dependence or firewalls as an integral part of quantum mechanics in the presence of black holes.".

 

[Haelfix]

Yet another characteristically beautiful paper on black hole Firewalls by Susskind. This reads as somewhat of a review of recent arguments, but it really sharpens a lot of the confusion and argumentation from the firewall conference at KITP in August. I find the sections on precursor states and its generalizations really satisfying.

http://arxiv.org/abs/1311.3335

 

[audioloop]

Yet another characteristically beautiful paper on black hole Firewalls by Susskind. This reads as somewhat of a review of recent arguments, but it really sharpens a lot of the confusion and argumentation from the firewall conference at KITP in August. I find the sections on precursor states and its generalizations really satisfying.

http://arxiv.org/abs/1311.3335

thanks for the paper.

read this

http://news.sciencemag.org/physics/2013/12/link-between-wormholes-and-quantum-entanglement



.

 

[audioloop]

Cool horizons for entangled black holes
http://arxiv.org/abs/1306.0533


then firewalls or cool horizons ?


http://data1.whicdn.com/images/32508178/broken-doll-fire-horror-terror-Favim.com-231939_large.gif

 

[PAllen]

When you've done all you want with your life, you can go and find out. You will have no trouble keeping the answer secret.

 

[audioloop]

very deep secret...


...lol...

 

[PAllen]

I guess the horizon firewall concept is slowly evaporating...

 

[Demystifier]

I guess the horizon firewall concept is slowly evaporating...

If the BH horizon evaporates, there is no doubt that it does so very slowly. But how slowly? As argued in
http://lanl.arxiv.org/abs/1311.4363
perhaps even slower than usually thought.