 Dynamics of Newtonian Gravitating Bodies

Kepler Problem > s.a. newtonian gravity; tests and violations.
* Idea: The problem of Newtonian motion in a 1/r central potential, like planetary motion around the Sun.
* Kepler's laws: (1) Law of ellipses, giving the shape of the orbit; (2) Law of areas, relating the speeds at different points from conservation of angular momentum; (3) Law of periods, P2 = (4π2/GM) a3 around a fixed center of attraction of mass M.
* Results: In velocity space, the motion follows a circle, either a complete one or just an arc.
* Perturbed: With the addition of a gravitational wave it becomes a Hill system.
* Symmetry group: An SO(4) algebra, generated by L and D:= A/(2m|E|)1/2, with A = Runge-Lenz vector,

[Li, Lj] = εijk Lk ,   [Di, Lj] = εijk Dk ,   [Di, Dj] = εijk Lk .

* Question: Show that the Moon's orbit around the Sun is convex [from ss].
@ General references: {& J Weinberg, SU seminar 1982}; Vogt AJP(96)apr [derivation of laws]; Derbes AJP(01)apr [hodographic solutions]; Osler AJP(01)oct [first law]; Cordani 03; Kowen & Mathur AJP(03)apr [geometry of orbits]; Nauenberg phy/05 [history: Hooke's contributions]; Chang & Hsiang a0801 [Newton and Kepler's laws]; Provost & Bracco EJP(09)-a0812 [without differential equations]; Pál MNRAS(09)-a0904 [analytical solution]; Wulfman JPA(09) [dynamical symmetries]; De Laurentis a1004; Xu EJP(12) [simple derivation of the first law using complex variables]; Unruh a1803 [simple derivation without calculus].
@ Perturbations: Chicone et al AIHP(96)gq/95, JMP(96)gq [gravitational radiation and "ionization"]; Gergely et al in(02)gq/07; Adkins & McDonnell PRD(07)gq, comment Chashchina & Silagadze PRD(08)-a0802 [and orbital precession]; Lemmon & Mondragon a1012/AJP [special-relativistic corrections]; Iorio IJMPD(15) [due to the oblateness of the central body].
@ In curved spaces: Abramowicz et al GRG(97), Abramowicz a1212 [perihelion precession]; Keane et al JMP(00)-a1411 [on spaces of constant curvature]; Cariñena et al JMP(05)mp, Pronko TMP(08)-a0705 [constant curvature]; Meng PAN(08)mp/05; Le Tiec CQG(12)-a1202 [Kepler's third law for circular orbits, post-Newtonian generalization, and the helical Killing vector]; Witzany & Lämmerzahl ApJ(17)-a1601 [pseudo-Newtonian limit for geodesics in arbitrary spacetimes].
@ Related topics: Gergely et al ApJS(00)gq/99 [true and eccentric anomaly]; Klačka & Gajdošík ap/99 [including galactic disk]; Abramowicz & Kluzniak GRG(03)gq/02 [and general relativity]; Hsiang et al EJP(11)-a1105 [for the Earth]; Borghi EJP(13) [adiabatic invariants, elementary introduction]; Horvathy FS-a1404 [Kepler's laws from the harmonic oscillator].
> Related topics: see Bertrand's Theorem; Kustaanheimo-Stiefel Transformation; Poynting-Robertson Effect; Runge-Lenz Vector; Symplectic Integrators.

Two-Body Problem > s.a. classical systems.
* Reduction: Can be expressed in terms of a body with the reduced mass μ = m1m2 / (m1+m2) orbiting a fixed mass m1 + m2 at a separation r = r1 + r2.

Three-Body Problem > s.a. classical systems; dynamics of gravitating bodies; geometric phase.
* Idea: A famously chaotic problem in Newtonian gravitation.
* Choreographic solution: One in which each massive particle moves periodically in a single closed orbit; One example is a stable figure-eight orbit, first found by Moore (1993) and re-discovered with its existence proof by Chenciner and Montgomery (2000); > s.a. motion of gravitating objects [in general relativity].
@ General references: Gutzwiller RMP(98) [Moon-Earth-Sun]; Posch & Thirring JMP(00); Henkel PhSc(01)phy/02 [Sundman solution]; Wardell MNRAS(02)gq, MNRAS(03)gq/02 [with radiation damping]; Mehmood et al mp/05 [closed form approximation of motion]; Šuvakov & Dmitrašinović PRL(13)-a1303 + news sci(13)mar [13 new families of solutions].
@ Periodic solutions: Chenciner & Montgomery AM(00)m.DS; Arioli CMP(02) [periodic, entropy]; Bistafa a2104 [Euler's exact syzygy solution].
@ Other related topics: Perdomo a1601 [relativistic restricted three-body problem, Lagrange points].