Standard form of master equations for general non-Markovian jump processes: The Laplace-space embedding framework and asymptotic solution

Abstract

We present a standard form of master equations (MEs) for general one-dimensional non-Markovian (history-dependent) jump processes, complemented by an asymptotic solution derived from an expanded system-size approach. The ME is obtained by developing a general Markovian embedding using a suitable set of auxiliary field variables. This Markovian embedding uses a Laplace-convolution operation applied to the velocity trajectory. We introduce an asymptotic method tailored for this ME standard, generalizing the system-size expansion for these jump processes. Under specific stability conditions tied to a single noise source, upon coarse graining, the generalized Langevin equation (GLE) emerges as a universal approximate model for point processes in the weak-coupling limit. This methodology offers a unified analytical tool set for general non-Markovian processes, reinforcing the universal applicability of the GLE founded in microdynamics and the principles of statistical physics. Published by the American Physical Society 2024