PuSH - Publication Server of Helmholtz Zentrum München

Chong, C.H.* ; Delerue, T. ; Mies, F.*

Rate-optimal estimation of mixed semimartingales.

Ann. Stat. 53, 219-244 (2025)
Postprint DOI
Open Access Green
Consider the sum Y = B + B(H) of a Brownian motion B and an independent fractional Brownian motion B(H) with Hurst parameter H ∈ (0, 1). Even though B(H) is not a semimartingale, it was shown by Cheridito (Bernoulli 7 (2001) 913–934) that Y is a semimartingale if H > 3/4. Moreover, Y is locally equivalent to B in this case, so H cannot be consistently estimated from local observations of Y. This paper pivots on another unexpected feature in this model: if B and B(H) become correlated, then Y will never be a semimartingale, and H can be identified, regardless of its value. This and other results will follow from a detailed statistical analysis of a more general class of processes called mixed semimartingales, which are semiparametric extensions of Y with stochastic volatility in both the martingale and the fractional component. In particular, we derive consistent estimators and feasible central limit theorems for all parameters and processes that can be identified from high-frequency observations. We further show that our estimators achieve optimal rates in a minimax sense.
Impact Factor
Scopus SNIP
Scopus
Cited By
Altmetric
3.700
3.395
1
Tags
Annotations
Special Publikation
Hide on homepage

Edit extra information
Edit own tags
Private
Edit own annotation
Private
Hide on publication lists
on hompage
Mark as special
publikation
Publication type Article: Journal article
Document type Scientific Article
Keywords Central Limit Theorem ; High-frequency Observations ; Hurst Parameter ; Kl Divergence ; Minimax Rate ; Mixed Fractional Brownian Motion ; Rough Noise
Language english
Publication Year 2025
HGF-reported in Year 2025
ISSN (print) / ISBN 0090-5364
Quellenangaben Volume: 53, Issue: 1, Pages: 219-244 Article Number: , Supplement: ,
Publisher Institute of Mathematical Statistics (IMS)
Reviewing status Peer reviewed
Institute(s) Institute of Epidemiology (EPI)
POF-Topic(s) 30202 - Environmental Health
Research field(s) Genetics and Epidemiology
PSP Element(s) G-504091-001
Scopus ID 85219079855
Erfassungsdatum 2025-05-06