Inferring nonlinear fractional diffusion processes from single trajectories

Autor: Kassel, Johannes A., Walter, Benjamin, Kantz, Holger
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1088/1367-2630/ad091e
Popis: We present a method to infer the arbitrary space-dependent drift and diffusion of a nonlinear stochastic model driven by multiplicative fractional Gaussian noise from a single trajectory. Our method, fractional Onsager-Machlup optimisation (fOMo), introduces a maximum likelihood estimator by minimising a field-theoretic action which we construct from the observed time series. We successfully test fOMo for a wide range of Hurst exponents using artificial data with strong nonlinearities, and apply it to a data set of daily mean temperatures. We further highlight the significant systematic estimation errors when ignoring non-Markovianity, underlining the need for nonlinear fractional inference methods when studying real-world long-range (anti-)correlated systems.
Comment: 21 pages, 5 figures, appendices
Databáze: arXiv