Analytic solution of the Mathisson–Papapetrou–Dixon equations
Derive an analytic solution of the coupled, nonlinear Mathisson–Papapetrou–Dixon equations governing the momentum, spin, and velocity of a spinning extended object in curved spacetime.
References
These are highly coupled, non-linear system of equations for which no analytic solution is known.
— On the Emergence of the Hysteresis Effect in Gravitational Systems
(2608.21269 - Moti et al., 21 Aug 2026) in Section III, immediately following equations (MP-Momentum)–(MP-Velocity)