Module pn 

Post-Newtonian gravity solver (Layer 4).

Implements relativistic corrections to Newtonian gravity:

• 1PN: O(v²/c²) corrections (perihelion precession)
• 2.5PN: O(v⁵/c⁵) gravitational radiation damping

Example: Mercury Perihelion Precession

use phyz_gravity::{GravityParticle, PostNewtonianSolver, GravitySolver};
use phyz_math::Vec3;

let m_sun = 1.989e30;
let m_mercury = 3.285e23;

let mut particles = vec![
    GravityParticle::new(Vec3::zeros(), Vec3::zeros(), m_sun),
    GravityParticle::new(
        Vec3::new(57.9e9, 0.0, 0.0),
        Vec3::new(0.0, 47.4e3, 0.0),
        m_mercury,
    ),
];

let mut solver = PostNewtonianSolver::new(1.0); // 1PN
solver.compute_forces(&mut particles);

References

• Blanchet (2014): “Gravitational Radiation from Post-Newtonian Sources”
• Will (2014): “The Confrontation between General Relativity and Experiment”

Structs

PostNewtonianSolver

Post-Newtonian gravity solver.

Functions

orbital_elements

Compute orbital elements from state.

perihelion_precession_rate

Compute perihelion precession rate (arcsec/century).