 Kramers–Moyal expansion

The Kramers-Moyal expansion Taylor-expands the gain terms of a jump-process master equation in the jump size. Keeping its first two terms yields a Fokker-Planck equation whose drift and diffusion coefficients are the first two infinitesimal jump moments.

The Kramers–Moyal expansion is a mathematical framework used in stochastic processes, particularly in the context of describing the dynamics of systems subjected to random influences. It provides a way to derive the Fokker-Planck equation, which governs the time evolution of the probability density function of a stochastic variable. **Key concepts of the Kramers-Moyal expansion:** 1.