High Quality Content by WIKIPEDIA articles! In physics, the Landau-Lifshitz-Gilbert equation , named for Lev Landau and Evgeny Lifshitz and T. L. Gilbert, is a name used for a differential equation describing the precessional motion of magnetization M in a solid. It is a modification by Gilbert of the original equation of Landau and Lifshitz.The LL equation was introduced by Landau & Lifshitz (1935) to model the precessional motion of magnetization M in a solid with an effective magnetic field Heff and with damping.The constant is the Landau-Lifshitz phenomenological damping parameter and depends on the solid, and is the electron gyromagnetic ratio.