Understanding the (restricted) three body problem

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SUMMARY

The discussion focuses on the restricted three-body problem, highlighting its 9 degrees of freedom and the insufficiency of 4 independent first integrals (center of mass, total momentum, total angular momentum, and total energy) for integrability. It emphasizes that in the inertial frame, the Lagrangian is time-dependent, leading to non-conservation of energy, while transforming to the synodic frame conserves certain quantities but complicates the total mechanical energy due to inertial forces. The Lagrangian points are identified as the only equilibrium points in the synodic frame. Key references include "Celestial Dynamics" by Dvorak and Lhotka.

PREREQUISITES
  • Understanding of the restricted three-body problem
  • Familiarity with Lagrangian and Hamiltonian mechanics
  • Knowledge of inertial and synodic reference frames
  • Basic principles of celestial dynamics
NEXT STEPS
  • Study the mathematical formulation of the restricted three-body problem
  • Learn about Lagrangian mechanics and its applications in celestial dynamics
  • Explore the concept of Lagrangian points and their significance
  • Read "Celestial Dynamics" by Dvorak and Lhotka for in-depth understanding
USEFUL FOR

Students and researchers in astrophysics, mathematicians specializing in dynamical systems, and anyone interested in the complexities of celestial mechanics and the restricted three-body problem.

throneoo
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Hello. Recently I've been trying to understand this problem but I'm not sure if I'm doing it correctly. So I'd like to show you some statements formed from my understanding on the subject and you guys could correct me if I'm wrong.

General:
1)The problem has 3*3=9 degrees of freedom and n independent first integrals is needed to solve it using quadrature (Integrable).

2)The independent first integrals here is the center of mass/ total momentum/ total angular momentum (3) and total energy (1) =4 which is not enough to be qualified as integrable.

Circularly restricted (3D)
3) In the inertial frame, the lagrangian is explicitly time dependent as the distances from the two massive bodies depend explicitly on time (constant rotation), hence both the lagrangian and hamiltonian are not conserved.

4)Transforming to the synodic (rotating) frame removes the explicit time dependence so those quantities are conserved, but the hamiltonian is not the total mechanical energy (due to the centrifugal and coriolis force)

5)Total energy is not conserved in the synodic frame due to the inertial forces. Presumably it is conserved in the inertial frame despite the fact that the gravitational influence from the smallest body is neglected.

6) The Lagrangian points are the only equilibrium points in the synodic frame.

Thanks for your help! I might add more to the thread.
 
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This is an interesting problem for me, too. What books are you using?
 
dextercioby said:
This is an interesting problem for me, too. What books are you using?
Celestial Dynamics by Dvorak and Lhotka is the main text. I also read a lot of articles on this subject
 

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