Contents

• • Preface
    • The Art of Computational Science
    • Extreme Research
    • Variational Programming
    • An Open Source Project
  
  
• List of Figures
• List of Codes
• List of Output
• List of Exercises
• I. Background
  • 1. The Universe in a Computer
    • 1.1 Gravity
    • 1.2 Galactic Suburbia
    • 1.3 Globular Clusters
    • 1.4 Galactic Nuclei
    • 1.5 Star Forming Regions
    • 1.6 Open Clusters
    • 1.7 Writing your own star cluster simulator
  
  
• II. Exploring -Body Algorithms
  • 2. Getting Started on the -Body problem
    • 2.1 Our Setting
    • 2.2 The Gravitational -Body Problem
    • 2.3 The Gravitational -Body Problem
  • 3. Exploring with a Forward-Euler Algorithm
    • 3.1 Choosing an Algorithm
    • 3.2 Writing a Code
    • 3.3 Running a Code
    • 3.4 Extending a Code
    • 3.5 Plotting and Printing
    • 3.6 Finding (slow) Convergence
    • 3.7 Checking Energy Conservation
  • 4. Exploring with a Leapfrog Algorithm
    • 4.1 Two Ways to Write the Leapfrog
    • 4.2 A Simple Leapfrog for the 2-Body Problem
    • 4.3 Finding Better Convergence
  • 5. Exploring with a Leapfrog Algorithm
    • 5.1 A More General Leapfrog
    • 5.2 Coordinates in the Center of Mass System
    • 5.3 Setting up Three Stars on a Circle
    • 5.4 Looking for Instabilities
    • 5.5 Priming the Pump
    • 5.6 Reaching Convergence
    • 5.7 The End of the Story
    • 5.8 Three Bodies on a Figure Eight
  • 6. Exploring with a Hermite Algorithm
    • 6.1 A Surprisingly Simple Hermite Scheme
    • 6.2 Comparison with the Leapfrog
    • 6.3 Snap, Crackle, and Pop
    • 6.4 Implementing Hermite
    • 6.5 Testing the Hermite: Three Stars on a Circle
    • 6.6 The Hermite Soars: Three Bodies on a Figure Eight
  
  
• III. Writing -body Codes
  • 7. A General -Body Hermite Code
    • 7.1 A Wish List
    • 7.2 A Standard -Body Snapshot Format
    • 7.3 A More Modular Approach: Functions
    • 7.4 Variable Time Steps: a Simple Collision Criterium
    • 7.5 Variable Time Steps: Better Collision Criteria
    • 7.6 Further Improvements
  • 8. A More Modular -Body Hermite Code
    • 8.1 Starting a Tool Box
    • 8.2 Gravitylab
    • 8.3 Introductory Comments
    • 8.4 Include Statements, Function Declarations, etc.
    • 8.5 The Function main()
    • 8.6 Command Line Options
    • 8.7 Snapshot Input
    • 8.8 Snapshot Output
    • 8.9 Reporting Diagnostics
    • 8.10 Orbit Integration
    • 8.11 Taking a Single Integration Step
    • 8.12 The Predictor Step
    • 8.13 The Corrector Step
    • 8.14 Where All the Work is Done
    • 8.15 Closing Logo
  
  
• IV. Performing -body Experiments
  • 9. Setting up a Star Cluster
    • 9.1 A Model for a Star Cluster
    • 9.2 Implementation: a Sphere in Cold Start
    • 9.3 Testing, testing, . . .
    • 9.4 Chasing the Bug
  • 10. A 25-body Example
    • 10.1 A -body run
    • 10.2 Making gnuplot movies
    • 10.3 Performing an experiment
  • 11. Fishing for Binaries
    • 11.1 Binary Dynamics
    • 11.2 Finding Binaries
    • 11.3 Finding Tight Binaries
    • 11.4 Dynamically Produced Binaries
  
  
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