OleMiss Colloquium

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Black holes everywhere! 40 10 years after
Vitor Cardoso (CENTRA/IST-Lisbon U.
Mississippi)?
17 Feb, OleMiss Colloquium
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Black holes everywhere!
A Journey That Begins Where Everything Ends
Infinite Space, Infinite Terror
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Black holes everywhere!
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What is a black hole?
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First, Something Simpler Stars Pressure
Balances Gravity
From www.astronomynotes.com
The Sun
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Eluding Gravitys Grasp

Escape Velocity
Escape Velocity Speed Needed To Escape An
Objects Gravitational Pull
Mass M Radius R
Earth Vesc 27,000 miles/hour (11 km/s) Sun
Vesc 1.4 million miles/hour (600 km/s)
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Origins of the Classical Definition
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Dark Stars Rev. John Michell (1783)
Pierre-Simon Laplace (1796)
Speed of light 1 billion miles/hour (3x105 km/s)

• What if a star were so small,
• escape speed gt speed of light?
• A star we couldnt see!

Earth mass R 1 inch Solar mass R 2
miles
Vesc speed of light ?
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1915 General Relativity, Einsteins Theory of
Gravity 1916 Schwarzschilds Discovery of BHs
in GRBHs only understood accepted in the
1960s (Term Black Hole coined by John Wheeler
in 1967)
Albert Einstein
Karl Schwarzschild
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Black Holes in GR
If an object is small enough, gravity overwhelms
pressure and the object collapses. Gravity is so
strong that nothing, not even light, can escape.
Radius of a BH 2 miles for Sun 1
inch for Earth NOT a solid surface All Mass at
the Center
(GR not valid there)
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Dispelling the Myths

• BHs are not cosmic vacuum
• cleaners only inside the horizon
• is matter pulled inexorably inward
• Far away from a BH, gravity
• is no different than for any
• other object with the same mass
• If a BH were to replace the sun, the orbits of
  planets, asteroids, moons, etc., would be
  unchanged
• (though it would get really really cold).

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Crash course on black holes

• Cosmic Censorship
• Penrose, 1970s

• Black holes have no hair Wheeler, 1971

• Membrane paradigm
• Thorne et al

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Continued

• (Classical) Laws of thermodynamics
• Bekenstein, Carter

• 0th surface gravity (temperature) is constant
  for stationary BH
• 1st Energy conservation during
  interactions
• 2nd area (entropy) increases with
  time (classically)
• 3rd impossible to reach T0 through finite
  number of processes

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Continued

• Thermodynamics
• - When quantum processes are taken into
  account, BHs really are thermodynamic objects,
  emitting Hawking radiation of temperature
  proportional to surface gravity
• leads to many interesting questions
  and puzzles related to what the microscopic
  degrees of freedom of a black hole are, possible
  information loss and lack of unitarity of
  quantum mechanics, etc.
• Entropy is proportional to area, so the DOF are
  somehow contained in some boundary...this
  eventually led to the holographic principle

• Black holes evaporate
• Hawking, 1974

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Black Holes in Astrophysics
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How do we find BHs in Nature?
Sidney Harris
Its black, and it looks like a hole. Id say
its a black hole.
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Where are BHs Found?
Centers of Galaxies
Binary Stars
1 BIG BH per galaxy million-billion x mass of
sun formation not fully understood
Millions of little BHs per galaxy 10 x mass
of sun formed by collapse of a massive star
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How do we know its a BH?

• Nature is tricky couldnt it be another small
  star
• like a neutron star or a white dwarf?
• Measure mass of X-ray star by motion of its
  companion (a star like the sun)
• Mass gt 3 solar masses
• ? BH!
• Roughly a dozen BHs found this way (tip of the
  iceberg)

Chandrasekhar
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The Milky Way Galaxy 100,000 light-years
across
Scale Size of Solar System 0.01 light-years
Typical Distance btw Stars 1
light-year
4 106 Msun Black Hole
Central BH Mass 4 million Msun Also
millions of 10 Msun BHs
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Movie time! Black holes from NS mergers
Next movie courtesy of Ralf Kaehler (AEI/ZIB) e
Bruno Giacomazzo, LR (AEI)
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Black holes can be seen is various windows too
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Black holes have no hair
E. Berti, V. C. C. M. Will, Phys.Rev.D73064030,
2006
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Black Holes in HEPI. XL Dimensions
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Flatland
Edwin Abbott Abbott, 1884
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Kaluza-Klein

• Long, long time ago (1920s) Kaluza Klein tried
  to unify gravity EM in 5 dimensions
• Idea didnt work 100 ....
• ... And was forgotten for many years

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Brane New world

• String Theory created generalized interest in
  gravity and Extra Dimensions (1990s)

• Gravity (closed strings) propagates in ED
• Gauge fields (open strings) are attached to branes

Extra Dimensions
Photons, etc
Graviton
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BraneWorld

• Braneworlds open new possibilities

At large distances, one recovers Newtons gravity!
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Black holes at the LHC
NYT, 9/11/01
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Black holes at the LHC

• But lets not blow it out of proportion...

Le grand faiseur de trous noirs a été victime
dune panne de courant (The large BH maker has
been the victim of a power supply failure)
the collisions may create mini-BHs. Many CERN
scientists say that these would not be dangerous,
since they would evaporate. However, some believe
this would put an end to our world.
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Black Holes in HEPII. The AdS/CFT
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The AdS/CFT

• Quantum gravity in AdS is the same as a conformal
  field theory on the boundary

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Field Theory Gravity
theory
Gauge Theories QCD
Quantum Gravity String theory
Use the field theory to learn about gravity Use
the gravity description to learn about the field
theory
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N4 SYM plasma via AdS/CFT
Vacuum
Empty AdS5
gYM2 N
L4/?2
? L3/2 G5
N2
J. Maldacena hep-th/9711200
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N4 SYM plasma via AdS/CFT

Thermal state
Empty AdS5
Vacuum
AdS5 BH
gYM2 N
L4/?2
? L3/2 G5
N2
Horizon radius
Temperature
E. Witten hep-th/9802150
J. Maldacena hep-th/9711200
Entropy SGRAVITY Area of the horizon
SFIELD THEORY Log Number of states
Evolution Unitary, no information loss
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BHs and Fundamental Physics

• BH oscillations describe relaxation of CFT to
  thermal state
• BH collisions probably describe formations and
  evolution aspects of quark-gluon plasma in HIC
  (e.g. RHIC)
• Hairy BHs in bulk and condensed matter physics
  (superconductors, Nernst effect, Hall effect)?
• ADD e Randall-Sundrum extra-large dimensions

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BHs as models for strongly interacting fluids.

• A black hole corresponds to a gas (or fluids)
  made of strongly interacting gluons.
• We can compute properties of this fluid using the
  gravity description.
• Einstein equations in the bulk ? fluid dynamics
  equations from the point of view of the boundary
  theory
• Shear viscosity ? classical damping of horizon
  fluctuations
• Conjecture
• lower limit on shear viscosity / entropy
  density?

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A viscosity bound conjecture
?
?
?
?
P.Kovtun, D.Son, Starinets, hep-th/0309213,
hep-th/0405231
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Black holes in the Lab?!
QCD ? 5d string theory
High energy collision? produces a black hole
droplet of
deconfined phase
quark gluon plasma .
Black hole? Very low shear viscosity? similar to
what is observed at RHIC the most perfect
fluid
Very rough model, we do not yet know the precise
string theory
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Black holes in the water tap
V.C Dias, Phys. Rev. Lett. 96, 181601 (2006)

• Black string

• Perturb the BS

• S-wave perturbations

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Black holes in the Lab?!
Plateau, 1849 Rayleigh, 1878
Water in my kitchen faucet
Rain (with high speed camera)
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Extensions
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Movie time! New black hole phases?
Next movie courtesy of Richard Hill and Lawrence
Eaves (Nottingham)
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BHs everywhere!

• Physicists said BHs could exist
• The ultimate victory of gravity over all other
  forces
• Astronomers find that BHs do exist
• 1 BIG BH per galaxy (1million-billion solar
  masses)
• Millions of lttlre BHs per galaxy (one solar
  mass)
• TeV-energy collisions form particles
• Maybe LHC or cosmic rays are black hole factories
• The AdS/CFT
• regardless of string theory, the AdS/CFT is
  beginning to describe an increasing spectrum of
  phenomena via BH physics in AdS spacetime
• Ringdown of a black hole describes relaxation to
  a thermal state in a CFT
• BH collisions describe formation of the
  quark-gluon plasma at RHIC
• BHS and fluids

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Thank you