Gravitational Lensing

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In Honor of Richard Tapia
Is there a 5th dimension?
Arlie Petters Duke University
Tapia 70, May 29, 2009
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Einstein 1915 General Relativity

• Our universe is 4D 1 Time 3D-Space

• Space and time are not independent
• - form a spacetime continuum

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Einstein 1915 General Relativity

• Massive objects deform spacetime
• - causes gravitational lensing

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Gravitational Lensing by Star

• 1936 Einstein (Science 84, 506)

source
B
A
star
DOUBLE IMAGES
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Courtesy J. Wambsganss
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Gravitational Lensing Assumes thatSpace is
3-Dimensional
Einstein made this assumption
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Geometry

• Cube (3D) 8 vertices, 12 edges, 6 squares
• Hypercube (4D) 16 vertices, 32 edges,
• 24 squares,
  8 cubes

HYPERCUBE
OUR UNIVERSE
CUBE
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Geometry
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Detecting Extra-Solar Planets
Shadow of Wire Hypercube
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Projection of Hypercube
Grande Ache, Paris Johann Otto von Spreckelsen
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Geometry
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Salvador Dali Crucifixion(Corpus Hypercubus)
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Does space have an
Extra Dimension?
Braneworld theory says, Yes!
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What is Braneworld Theory?

• String theory
• - elementary particles and forces arise from
• vibrating strings
• Braneworld theory
• - our universe floats in a 5D WORLD
• 1 Time 4D-Space!

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Braneworld TheoryRandall-Sundrum Formulation

• Our universe is a membrane (or brane) in a
• 5D World

DIRECTION OF 4th DIMENSION OF SPACE
BULK (OFF BRANE)
OUR UNIVERSE (BRANE)
Credits NYT Science
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Braneworld TheoryRandall-Sundrum Formulation

• All particles and forces in our universe, except
  gravity, are stuck on our brane

DIRECTION OF 4th DIMENSION OF SPACE
WE CANNOT TRAVEL BETWEEN BRANES
OUR UNIVERSE (BRANE)
Credits NYT Science
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How can we know that there is a 5th dimension?
Keeton Petters (2006)

• Find a braneworld black hole

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Braneworld Black Holes Versus Regular Black Holes

• Mini black holes formed in early universe

early universe
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Braneworld Black Holes Versus Regular Black Holes

• Microscopic black holes in Einsteins theory
• Mass less than asteroid
  Fizzled out by now

asteroid
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Braneworld Black Holes Versus Regular Black Holes

• Microscopic black holes in braneworld theory
• Mass less than asteroid Could
  exist today

asteroid
early universe
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How to detect a braneworld black hole?
Keeton Petters (2006)

• Braneworld black holes imprint on light

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Wave Nature of Light

• 1801 Thomas Youngs double slit experiment

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Gravitational Lensing
lens plane
B
observer
star
source
A
Einstein Double Images
Interpret as a Young double slit experiment
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Double Images as Young Double Slit
lens plane
Fringe Pattern
source
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How to detect a braneworld black hole?
Fringe Pattern
lens plane
source
braneworld black hole
Keeton Petters (2006)
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How to detect a braneworld black hole?
Keeton Petters (2006)

• Look for fringe patterns from braneworld black
  hole lensing

Gamma Ray Bursts
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Predicted Gamma Ray Fringe Pattern due to a
Braneworld Black Hole
Keeton Petters (2006)
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FERMI Gamma-Ray Space Telescope
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In Honor of Richard Tapia