scholarly journals HPS meets AMPS: how soft hair dissolves the firewall

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Sabrina Pasterski ◽  
Herman Verlinde
Keyword(s):  
Black Hole ◽  
Degrees Of Freedom ◽  
Essential Role ◽  
Soft Mode ◽  
Black Hole Entropy ◽  
Transition Function ◽  
Goldstone Mode ◽  
Subspace Projection ◽  
Classical Transition ◽  
Black Hole Interior

Abstract We build on the observation by Hawking, Perry and Strominger that a global black hole space-time supports a large number of soft hair degrees of freedom to shed new light on the firewall argument by Almheiri, Marolf, Polchinski, and Sully. We propose that the soft hair Goldstone mode is encoded in a classical transition function that connects the asymptotic and near horizon region. The entropy carried by the soft hair is part of the black hole entropy and encoded in the outside geometry. We argue that the infalling observer automatically measures the classical value of the soft mode before reaching the horizon and that this measurement implements a code subspace projection that enables the reconstruction of interior operators. We use the soft hair dynamics to introduce an observer dependent notion of the firewall and show that for an infalling observer it recedes inwards into the black hole interior: the observer never encounters a firewall before reaching the singularity. Our results indicate that the HPS black hole soft hair plays an essential role in dissolving the AMPS firewall.

scholarly journals ENTROPY AND AREA IN LOOP QUANTUM GRAVITY

2005 ◽  
Vol 14 (12) ◽  
pp. 2301-2305
Author(s):  
JOHN SWAIN
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Maximum Entropy ◽  
Degrees Of Freedom ◽  
Loop Quantum Gravity ◽  
Black Hole Entropy ◽  
Black Hole Thermodynamics ◽  
Three Dimensions ◽  
Spin Network

Black hole thermodynamics suggests that the maximum entropy that can be contained in a region of space is proportional to the area enclosing it rather than its volume. We argue that this follows naturally from loop quantum gravity and a result of Kolmogorov and Bardzin' on the the realizability of networks in three dimensions. This represents an alternative to other approaches in which some sort of correlation between field configurations helps limit the degrees of freedom within a region. It also provides an approach to thinking about black hole entropy in terms of states inside rather than on its surface. Intuitively, a spin network complicated enough to imbue a region with volume only lets that volume grow as quickly as the area bounding it.

SIGNATURES OF AN EMERGENT GRAVITY FROM BLACK HOLE ENTROPY

2009 ◽  
Vol 18 (14) ◽  
pp. 2323-2327
Author(s):  
CENALO VAZ
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Mass Spectrum ◽  
Partition Function ◽  
Ground State ◽  
Degrees Of Freedom ◽  
Thermodynamic Description ◽  
Black Hole Entropy ◽  
Fundamental Particle ◽  
Horizon Radius

The existence of a thermodynamic description of horizons indicates that space–time has a microstructure. While the "fundamental" degrees of freedom remain elusive, quantizing Einstein's gravity provides some clues about their properties. A quantum AdS black hole possesses an equispaced mass spectrum, independent of Newton's constant, G, when its horizon radius is large compared to the AdS length. Moreover, the black hole's thermodynamics in this limit is inextricably connected with its thermodynamics in the opposite (Schwarzschild) limit by a duality of the Bose partition function. G, absent in the mass spectrum, re-emerges in the thermodynamic description through the Schwarzschild limit, which should be viewed as a natural "ground state." It seems that the Hawking–Page phase transition separates fundamental, "particle-like" degrees of freedom from effective, "geometric" ones.

scholarly journals HOLOGRAPHY, GAUGE-GRAVITY CONNECTION AND BLACK HOLE ENTROPY

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3414-3425 ◽  
Author(s):  
PARTHASARATHI MAJUMDAR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Black Hole Entropy ◽  
Cross Sectional ◽  
Gauge Gravity ◽  
Thermal Stability Of ◽  
Spacetime Fluctuations ◽  
Area Law ◽  
Quantum Spacetime

The issues of holography and possible links with gauge theories in spacetime physics is discussed, in an approach quite distinct from the more restricted AdS-CFT correspondence. A particular notion of holography in the context of black hole thermodynamics is derived (rather than conjectured) from rather elementary considerations, which also leads to a criterion of thermal stability of radiant black holes, without resorting to specific classical metrics. For black holes that obey this criterion, the canonical entropy is expressed in terms of the microcanonical entropy of an Isolated Horizon which is essentially a local generalization of the very global event horizon and is a null inner boundary of spacetime, with marginal outer trapping. It is argued why degrees of freedom on this horizon must be described by a topological gauge theory. Quantizing this boundary theory leads to the microcanonical entropy of the horizon expressed in terms of an infinite series asymptotic in the cross-sectional area, with the leading 'area-law' term followed by finite, unambiguously calculable corrections arising from quantum spacetime fluctuations.

scholarly journals A NEW APPROACH TO BLACK HOLE MICROSTATES

1998 ◽  
Vol 13 (23) ◽  
pp. 1875-1879 ◽  
Author(s):  
RICHARD J. EPP ◽  
R. B. MANN
Keyword(s):  
Black Hole ◽  
Degrees Of Freedom ◽  
Black Hole Entropy ◽  
Space Time ◽  
Orthonormal Frame ◽  
Great Promise ◽  
Frame Field ◽  
New Approach ◽  
Four Dimensions ◽  
First Order

If one encodes the gravitational degrees of freedom in an orthonormal frame field, there is a very natural first-order action one can write down (which in four dimensions is known as the Goldberg action). In this letter we will show that this action contains a boundary action for certain microscopic degrees of freedom living at the horizon of a black hole, and argue that these degrees of freedom hold great promise for explaining the microstates responsible for black hole entropy, in any number of space–time dimensions. This approach faces many interesting challenges, both technical and conceptual.

scholarly journals FROM BRICKS TO QUASINORMAL MODES: A NEW PERSPECTIVE ON BLACK HOLE ENTROPY

2013 ◽  
Vol 22 (12) ◽  
pp. 1342027 ◽  
Author(s):  
MICHELE ARZANO ◽  
STEFANO BIANCO ◽  
OLAF DREYER
Keyword(s):  
Black Hole ◽  
Short Distance ◽  
Degrees Of Freedom ◽  
Quasinormal Modes ◽  
Black Hole Entropy ◽  
Quantum Field ◽  
Extended Region ◽  
New Perspective ◽  
The Right ◽  
Dynamical Degrees

Calculations of black hole entropy based on the counting of modes of a quantum field propagating in a Schwarzschild background need to be regularized in the vicinity of the horizon. To obtain the Bekenstein–Hawking result, the short distance cut-off needs to be fixed by hand. In this note, we give an argument for obtaining this cut-off in a natural fashion. We do this by modeling the black hole by its set of quasinormal modes (QNMs). The horizon then becomes a extended region: the quantum ergosphere. The interaction of the quantum ergosphere and the quantum field provides a natural regularization mechanism. The width of the quantum ergosphere provides the right cut-off for the entropy calculation. We arrive at a dual picture of black hole entropy. The entropy of the black hole is given both by the entropy of the quantum field in the bulk and the dynamical degrees of freedom on the horizon.

scholarly journals Where are the degrees of freedom responsible for black-hole entropy?

2008 ◽  
Vol 86 (4) ◽  
pp. 653-658 ◽  
Author(s):  
S Das ◽  
S Shankaranarayanan ◽  
S Sur
Keyword(s):  
Black Hole ◽  
Excited State ◽  
Power Law ◽  
Ground State ◽  
Degrees Of Freedom ◽  
Black Hole Entropy ◽  
Quantum Field ◽  
Hole Area ◽  
Area Law ◽  
03.65 Ud

Considering the entanglement between quantum field degrees of freedom inside and outside the horizon as a plausible source of black-hole entropy, we address the question: where are the degrees of freedom that give rise to this entropy located? When the field is in ground state, the black-hole area law is obeyed and the degrees of freedom near the horizon contribute most to the entropy. However, for excited state, or a superposition of ground state and excited state, power-law corrections to the area law are obtained, and more significant contributions from the degrees of freedom far from the horizon are shown.PACS Nos.: 04.60.–m, 04.62., 04.70.–s, 03.65.Ud

scholarly journals The temperature/entropy connection for horizons, massless particle scattering, and the origin of locality

2015 ◽  
Vol 24 (12) ◽  
pp. 1544010 ◽  
Author(s):  
Tom Banks
Keyword(s):  
Black Hole ◽  
Energy Density ◽  
Degrees Of Freedom ◽  
Black Hole Entropy ◽  
Massless Particle ◽  
Finite Energy ◽  
Fine Tuning ◽  
Finite Model ◽  
Particle Scattering ◽  
Null Infinity

I explain, in nontechnical terms, the basic ideas of holographic spacetime (HST) models of quantum gravity (QG). The key feature is that the degrees of freedom (DOF) of QG, localized in a finite causal diamond are restrictions of an algebra of asymptotic currents, describing flows of quantum numbers out to null infinity in Minkowski space, with zero energy density on the sphere at infinity. Finite energy density states are constrained states of these DOF and the resulting relation between asymptotic energy and the number of constraints, explains the relation between black hole entropy and energy, as well as the critical energy/impact parameter regime in which particle scattering leads to black hole formation. The results of a general class of models, implementing these principles, are described, and applied to understand the firewall paradox, and to construct a finite model of the early universe, which implements inflation with only the minimal fine-tuning needed to obtain a universe containing localized excitations more complex than large black holes.

scholarly journals Truly two-dimensional black holes under dimensional transitions of spacetime

2021 ◽  
Author(s):  
Wanpeng Tan
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Massive Star ◽  
Majorana Fermions ◽  
Two Dimensional ◽  
Gauge Bosons ◽  
The Core ◽  
Black Hole Interior

A sufficiently massive star in the end of its life will inevitably collapse into a black hole as more deconfined degrees of freedom make the core ever softer. One possible way to avoid the singularity in the end is by dimensional phase transition of spacetime. Indeed, the black hole interior, two-dimensional in nature, can be described well as a perfect fluid of free massless Majorana fermions and gauge bosons under a 2-d supersymmetric mirror model with new understanding of emergent gravity from dimensional evolution of spacetime. In particular, the 2-d conformal invariance of the black hole gives rise to desired consistent results for the interior microphysics and structures including its temperature, density, and entropy.

BLACK HOLE ENTROPY IN THE MEMBRANE PARADIGM

2002 ◽  
Vol 11 (05) ◽  
pp. 789-804 ◽  
Author(s):  
TAKESHI SHIMOMURA ◽  
TAKASHI OKAMURA ◽  
TAKASHI MISHIMA
Keyword(s):  
Black Hole ◽  
Degrees Of Freedom ◽  
Black Hole Entropy ◽  
Second Law Of Thermodynamics ◽  
Local Observable ◽  
General Process ◽  
Entropy Formula ◽  
Generalized Second Law ◽  
Fluid Membrane ◽  
Physical Quantities

We study whether the black hole entropy can be understood in terms of thermodynamical properties of a fluid membrane in the Membrane Paradigm. In particular, by using local observable quantities of the membrane and thermodynamical relations, we calculate the entropy of the membrane in a phenomenological manner. It is shown that one can assign the entropy [Formula: see text] of black hole to that of the membrane such that the entropy, together with other physical quantities of the membrane, composes thermodynamics consistently. This result concerning entropy gives a new support for the Membrane Paradigm, and consequently, supports a kind of holographic viewpoint about black hole for external observers, i.e., black hole entropy for external observers can be regarded consistently as a measure of some degrees of freedom associated with the horizon boundary. In addition, our result also suggests that the generalized second law of thermodynamics hold in quite general process.

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