Improving Swift

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Improving Swift
Hal Levison, PI (SwRI) David Kaufmann
(SwRI) Mark Lewis (Trinity Univ.) Martin Duncan
(Queens Univ.)
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What is Swift?

• Simulation software for planetary system dynamics
• Developed by Levison and Duncan
• www.boulder.swri.edu/hal/swift.html
• Most important integration algorithms
• Wisdom-Holman Mapping (WHM)
• Regularized Mixed Variable Symplectic (RMVS)
  algorithm

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Symplectic Integrators

• Derived from a Hamiltonian, H(q,p,t)
• Gravitational N-body Hamiltonian
• Piecewise, palindromic integration yields a
  symplectic algorithm
• 1st order example HA(?) HB(?)
• 2nd order example HA(?/2) HB(?) HA(?/2)

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Project Goals

• Incorporate SyMBA (Symplectic Massive Body
  Algorithm) into the Swift package
• Completely rewrite Swift ? Swifter
• www.boulder.swri.edu/swifter/
• Develop the SwiftVis data analysis and
  visualization package
• www.cs.trinity.edu/mlewis/SwiftVis/
• Symplectic tree code

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The Nice Model

• Current theories of planet formation have
  difficulty explaining
• The eccentricities and mutual inclinations of the
  giant planets
• The inclinations of Jupiters Trojan asteroids
• The Late Heavy Bombardment (LHB)
• These seem to be explained by an early passage of
  Jupiter and Saturn through their 12 mean motion
  resonance

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The Nice Model
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The Nice Model
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The Nice Model
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The Nice Model

• Tsiganis, Gomes, Morbidelli, Levison. Origin
  of the orbital architecture of the giant planets
  of the Solar System. Nature, May 2005.
• Morbidelli, Levison, Tsiganis, Gomes. Chaotic
  capture of Jupiters Trojan asteroids in the
  early Solar System. Nature, May 2005.
• Gomes, Levison, Tsiganis, Morbidelli. Origin
  of the cataclysmic Late Heavy Bombardment period
  of the terrestrial planets. Nature, May 2005.