Black Hole Microstates, and the Information Paradox

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Black Hole Microstates, and the Information
Paradox

• Iosif Bena
• IPhT (SPhT), CEA Saclay

With Nick Warner, Clement Ruef, Nikolay Bobev and
Stefano Giusto
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Strominger and Vafa (1996) 1000 other articles
Count BH Microstates Match B.H. entropy !!!
2 ways to understand

Finite Gravity
Zero Gravity
FILL
AdS-CFT Correspondence
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Strominger and Vafa (1996) Count Black Hole
Microstates (branes strings) Correctly match
B.H. entropy !!!
Zero Gravity
Black hole regime of parameters

• Standard lore
• As gravity becomes stronger,- brane
  configuration becomes smaller
• horizon develops and engulfs it
• recover standard black hole

Susskind Horowitz, Polchinski Damour, Veneziano
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Strominger and Vafa (1996) Count Black Hole
Microstates (branes strings) Correctly match
B.H. entropy !!!
Zero Gravity
Black hole regime of parameters
Identical to black hole far away. Horizon ?
Smooth cap

Giusto, Mathur, Saxena Bena, Warner Berglund,
Gimon, Levi
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BIG QUESTION Are all black hole microstates
becoming geometries with no horizon ?
?

• Black hole ensemble of horizonless microstates

Mathur friends
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Analogy with ideal gas
Statistical Physics (Air -- molecules) eS
microstates typical atypical
Thermodynamics (Air ideal gas) P V n R TdE
T dS P dV
Thermodynamics Black Hole Solution
Statistical Physics Microstate geometries
Long distance physics Gravitational lensing
Physics at horizon Information loss
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A few corollaires
new low-mass degrees of freedom
- Thermodynamics (LQF T) breaks down at horizon.
Nonlocal effects take over. - No spacetime
inside black holes. Quantum superposition of
microstate geometries.
Can be proved by rigorous calculations
1. Build most generic microstates Count
2. Use AdS-CFT
8 parameters black hole charges
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Question

• Can a large blob of stuff replace BH ?
• Sure !!!
• AdS-QCD
• Plasma ball dual to BH in the bulk
• Recover all BH properties
• Absorption of incoming stuff
• Hawking radiation
• Key ingredient large number of degrees of
  freedom (N2)

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Word of caution

• To replace classical BH by BH-sized object
• Gravastar
• Fuzzball
• LQG muck
• Quark-star, you name it
• satisfy very stringent (mutilating)
  test Horowitz
• BH size grows with GN
• Size of objects in other theories becomes smaller

Same growth with GN !!!
- BH microstate geometries pass this test -
Highly nontrivial mechanism
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Microstates geometries
3-charge 5D black hole Strominger, Vafa BMPV
Want solutions with same asymptotics, but no
horizon
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Microstates geometries
Bena, Warner Gutowski, Reall
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Microstates geometries
Linear system 4 layers
Charge coming from fluxes
Bena, Warner
Focus on Gibbons-Hawking (Taub-NUT) base
8 harmonic functions
Gauntlett, Gutowski, Bena, Kraus, Warner
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Ex Black Rings (in Taub-NUT) Elvang, Emparan,
Mateos, Reall Bena, Kraus, Warner Gaiotto,
Strominger, Yin
Explicit example of BH uniqueness violation in
5D BPS Black Saturns, even with BH away from BR
center Bena, Wang, Warner
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Microstates geometries
Giusto, Mathur, Saxena Bena, Warner Berglund,
Gimon, Levi
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Microstates geometries
Multi-center Taub-NUTmany 2-cycles flux
Compactified to 4D ? multicenter configuration
Abelian worldvolume flux Each 16 supercharges
4 common supercharges
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Microstates geometries

• Where is the BH charge ?
• L q A0
• L A0 F12 F23
• Where is the BH mass ?
• E F12 F12
• BH angular momentum
• J E x B F01 F12

2-cycles magnetic flux
magnetic
Charge disolved in fluxes Klebanov-Strassler
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A problem ?

• Hard to get microstates of real black holes
• All known solutions
• D1 D5 system Mathur, Lunin, Maldacena, Maoz,
  Taylor, Skenderis
• 3-charge (D1 D5 P) microstates in 5DGiusto,
  Mathur, Saxena Bena, Warner Berglund, Gimon,
  Levi
• 4-charge microstates in 4D Bena, Kraus Saxena
  Potvin, Giusto, Peet
• Nonextremal microstates Jejjala, Madden, Ross,
  Titchener (JMaRT) Giusto, Ross, Saxena
• did not have charge/mass/J of black hole with
  classically large event horizon (S gt 0, Q1 Q2 Q3
  gt J2)

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Microstates for Sgt0 black holes
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Microstates for Sgt0 black holes
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Microstates for Sgt0 black holes
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Microstates for Sgt0 black holes
Bena, Wang, Warner
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Deep microstates

• Deeper throat similar cap !
• Solution smooth throughout scaling
• Scaling goes on forever !!!
• Can quantum effects stop that ?
• Can they destroy huge chunk of smooth
  low-curvature horizonless solution ?

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More general solutions

• Spectral flow Bena, Bobev, WarnerGH solution
  solution with 2-charge supertube in GH
  background
• Supertubes Mateos, Townsend
• supersymmetric brane configurations
• arbitrary shape
• smooth supergravity solutionsLunin, Mathur
  Lunin, Maldacena, Maoz
• Classical moduli space of microstates solutions
  has infinite dimension !

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More general solutions

• Problem 2-charge supertubes have 2 charges
• Marolf, Palmer Rychkov
• Solution
• In deep scaling solutions Bena, Bobev, Ruef,
  Warner
• Entropy enhancement !!!
• smooth sugra solutions

STUBE ltlt SBH
TUBE
ENHANCED
STUBE SBH
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Black Hole DeconstructionDenef, Gaiotto,
Strominger, Van den Bleeken, Yin (2007) S SBH
Black Holes
Strominger - Vafa S SBH
Effective coupling ( gs )
Smooth Horizonless Microstate Geometries
Multicenter Quiver QMDenef, Moore (2007) S SBH
Size grows
No Horizon
Same ingredients Scaling solutions of primitive
centers
Punchline Typical states grow as GN increases.
Horizon never forms.
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A bit of AdS-CFT

• Every asymptotically AdS microstate geometry
  dual to a microstate of the boundary CFT
• CFT has typical sector (where the states giving
  BH entropy live) and atypical sectors.
• Calculate mass gap of microstate geometries
  match with CFT mass gap.
• Deep microstates ? CFT states in typical sector !
  
• Holographic anatomy Taylor, Skenderis

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Black Holes in AdS-CFT Option 1

• Each state has horizonless bulk dual Mathur
• Classical BH solution thermodynamic
  approximation
• Lots of microstates dual to CFT states in
  typical sector
• Size grows with BH horizon.
• Finite mass-gap - agrees with CFT expectation
  Maldacena
• Natural continuation of Denef-Moore, DGSVY

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Black Holes in AdS-CFT Option 2

• Typical CFT states have no individual bulk
  duals.
• Many states mapped into one BH solution
• Some states in typical CFT sector do have bulk
  duals.
• 1 to 1 map in all other understood systems
  (D1-D5, LLM, Polchinski-Strassler). Why
  different ?

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Black Holes in AdS-CFT Option 3

• Typical states have bulk duals with horizon (
  BH)
• States in the typical sector of CFT have both
  infinite and finite throats.
• CFT microstates have mass-gap and Heisenberg
  recurrence. Would-be bulk solutions do not.
• Maldacena Balasubramanian, Kraus, Shigemori

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Punchline

• In string theory BPS extremal black holes
  ensembles of horizonless microstates.
• Can be proven (disproven) rigorously
• No spacetime inside horizon. Instead quantum
  superposition of microstates
• No unitarity loss/information paradox

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Always asked question

• Why are quantum effects affecting the horizon
  (low curvature) ?
• Answer space-time has singularity
• low-mass degrees of freedom
• change the physics on long distances
• This is very common in string theory !!!
• Polchinski-Strassler
• Giant Gravitons LLM
• It can be even worse quantum effects
  significant even without horizon de Boer,
  El Showk, Messamah, van den Bleeken

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Extremal Black Holes

• This is not so strange
• Time-like singularity resolved by stringy
  low-mass modes extending to horizon

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What about nonextremal ?

• Given total energy budget
• most entropy obtained by making
  brane-antibrane pairs
• S2p (N11/2 N11/2)(N21/2 N21/2)(N31/2
  N31/2) Horowitz, Maldacena, Strominger
• Mass gap 1/N1N2N3
• Extend on long distances (horizon scale)
• More mass lower mass-gap larger size

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Experimental Consequences ?

• New light degrees of freedom at horizon.
  (independent of string theory)
• BH collisions
• - gravity waves LISA
• primordial BH formation

- continuous spectrum - democratic decay 82
hadrons, 18 leptons
- continuous spectrum - non-democratic decay
LHC Black Holes vs. Microstates
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Summary and Future Directions

• Strong evidence that in string theory BPS
  extremal black holes ensembles of microstates
• One may not care about extremal BHs
• One may not care about string theory
• Lesson is generic QG low-mass modes can change
  physics on large (horizon) scales
• Extend to non-extremal black holes
• Probably at least near-extremal
• Need more non-extremal microstates
• Only one solution known. Works very nicely.
  Jejjala Madden Ross Titchener (JMaRT) Myers
  al, Mathur al.
• Inverse scattering methods. Use JMaRT as seed.
• New light degrees of freedom. Experiment ?
• LISA horizon ring-down
• LHC non-democratic decay
• Supermassive BHs easier to form by mergers

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