Inferring nonlinear fractional diffusion processes from single trajectories

Autor: Johannes A Kassel, Benjamin Walter, Holger Kantz
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: New Journal of Physics, Vol 25, Iss 11, p 113036 (2023)
Druh dokumentu: article
ISSN: 1367-2630
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.
Databáze: Directory of Open Access Journals