Iguchi, Yuga;
Beskos, Alexandros;
Graham, Matthew M;
(2024)
Parameter inference for degenerate diffusion processes.
Stochastic Processes and their Applications
, 174
, Article 104384. 10.1016/j.spa.2024.104384.
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Abstract
We study parametric inference for ergodic diffusion processes with a degenerate diffusion matrix. Existing research focuses on a particular class of hypo-elliptic Stochastic Differential Equations (SDEs), with components split into ‘rough’/‘smooth’ and noise from rough components propagating directly onto smooth ones, but some critical model classes arising in applications have yet to be explored. We aim to cover this gap, thus analyse the highly degenerate class of SDEs, where components split into further sub-groups. Such models include e.g. the notable case of generalised Langevin equations. We propose a tailored time-discretisation scheme and provide asymptotic results supporting our scheme in the context of high-frequency, full observations. The proposed discretisation scheme is applicable in much more general data regimes and is shown to overcome biases via simulation studies also in the practical case when only a smooth component is observed. Joint consideration of our study for highly degenerate SDEs and existing research provides a general ‘recipe’ for the development of time-discretisation schemes to be used within statistical methods for general classes of hypo-elliptic SDEs.
Type: | Article |
---|---|
Title: | Parameter inference for degenerate diffusion processes |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1016/j.spa.2024.104384 |
Publisher version: | https://doi.org/10.1016/j.spa.2024.104384 |
Language: | English |
Additional information: | Copyright © 2024 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Stochastic differential equation; Hypo-elliptic diffusion; Hörmander’s condition; Partial observations; Generalised Langevin equation |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Statistical Science |
URI: | https://discovery.ucl.ac.uk/id/eprint/10206038 |
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