17,123 research outputs found
Black holes vs. firewalls and thermo-field dynamics
In this essay, we examine the implications of the ongoing black holes vs.
firewalls debate for the thermo-field dynamics of black holes by analyzing a
CFT in a thermal state in the context of AdS/CFT. We argue that the themo-field
doubled copy of the thermal CFT should be thought of not as a fictitious
system, but as the image of the CFT in the heat-bath. While this idea was
proposed earlier by Papadodimas et al., our following conclusions differ from
theirs. In case of strong coupling between the CFT and the heat-bath this image
allows for free infall through the horizon and the system is described by a
black hole. Conversely, firewalls are the appropriate dual description in case
of weak interaction of the CFT with its heat bath.Comment: 7 Pages, 4 figures. This essay received an honorable mention in the
2013 essay competition of the Gravity Research Foundation. v2: References
adde
Is Alice burning or fuzzing?
Recently, Almheiri, Marolf, Polchinski and Sully (AMPS) have suggested a
Gedankenexperiment to test black hole complementarity. They claim that the
postulates of black hole complementarity are mutually inconsistent and choose
to give up the "absence of drama" for an infalling observer. According to them
the black hole is shielded by a firewall no later than Page time. This has
generated some controversy. We find that an interesting picture emerges when we
take into account objections from the advocates of fuzzballs. We reformulate
AMPS' Gedankenexperiment in the decoherence picture of quantum mechanics and
find that low energy wave packets interact with the radiation quanta rather
violently while high energy wave packets do not. This is consistent with
Mathur's recent proposal of fuzzball complementarity for high energy quanta
falling into fuzzballs.Comment: 14 pages, 6 figures; v3: References added, discussions of some parts
changed substantially, conclusions unaltere
Multi-centered D1-D5 solutions at finite B-moduli
We study the fate of two-centered D1-D5 systems on T^4 away from the singular
supergravity point in the moduli space. We do this by considering a background
D1-D5 black hole with a self-dual B-field moduli turned on and treating the
second center in the probe limit in this background. We find that in general
marginal bound states at zero moduli become metastable at finite B-moduli,
demonstrating a breaking of supersymmetry. However, we also find evidence that
when the charges of both centers are comparable, the effects of supersymmetry
breaking become negligible. We show that this effect is independent of string
coupling and thus it should be possible to reproduce this in the CFT at weak
coupling. We comment on the implications for the fuzzball proposal.Comment: 19 pages + appendices, 14 figures; v2: added important remark in
example in introduction, rewrote first paragraph in sect 3.2 for clarity,
other misc. small edits; as accepted for publication in JHE
Firewalls in AdS/CFT
Several recent papers argue against firewalls by relaxing the requirement for
locality outside the stretched horizon. In the firewall argument, locality
essentially serves the purpose of ensuring that the degrees of freedom required
for infall are those in the proximity of the black hole and not the ones in the
early radiation. We make the firewall argument sharper by utilizing the AdS/CFT
framework and claim that the firewall argument essentially states that the dual
to a thermal state in the CFT is a firewall.Comment: 11 pages plus references, 8 figures; version accepted for publication
in JHE
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