Large sample autocovariance matrices of linear processes with heavy tails
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Large sample autocovariance matrices of linear processes with heavy tails. / Heiny, Johannes; Mikosch, Thomas.
I: Stochastic Processes and Their Applications, Bind 141, 2021, s. 344-375.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Large sample autocovariance matrices of linear processes with heavy tails
AU - Heiny, Johannes
AU - Mikosch, Thomas
N1 - Publisher Copyright: © 2021 Elsevier B.V.
PY - 2021
Y1 - 2021
N2 - We provide asymptotic theory for certain functions of the sample autocovariance matrices of a high-dimensional time series with infinite fourth moment. The time series exhibits linear dependence across the coordinates and through time. Assuming that the dimension increases with the sample size, we provide theory for the eigenvectors of the sample autocovariance matrices and find explicit approximations of a simple structure, whose finite sample quality is illustrated for simulated data. We also obtain the limits of the normalized eigenvalues of functions of the sample autocovariance matrices in terms of cluster Poisson point processes. In turn, we derive the distributional limits of the largest eigenvalues and functionals acting on them. In our proofs, we use large deviation techniques for heavy-tailed processes, point process techniques motivated by extreme value theory, and related continuous mapping arguments.
AB - We provide asymptotic theory for certain functions of the sample autocovariance matrices of a high-dimensional time series with infinite fourth moment. The time series exhibits linear dependence across the coordinates and through time. Assuming that the dimension increases with the sample size, we provide theory for the eigenvectors of the sample autocovariance matrices and find explicit approximations of a simple structure, whose finite sample quality is illustrated for simulated data. We also obtain the limits of the normalized eigenvalues of functions of the sample autocovariance matrices in terms of cluster Poisson point processes. In turn, we derive the distributional limits of the largest eigenvalues and functionals acting on them. In our proofs, we use large deviation techniques for heavy-tailed processes, point process techniques motivated by extreme value theory, and related continuous mapping arguments.
KW - Large deviations
KW - Largest eigenvalues
KW - Linearly dependent entries
KW - Point process convergence
KW - Regular variation
KW - Sample autocovariance matrix
UR - http://www.scopus.com/inward/record.url?scp=85112526827&partnerID=8YFLogxK
U2 - 10.1016/j.spa.2021.07.010
DO - 10.1016/j.spa.2021.07.010
M3 - Journal article
AN - SCOPUS:85112526827
VL - 141
SP - 344
EP - 375
JO - Stochastic Processes and their Applications
JF - Stochastic Processes and their Applications
SN - 0304-4149
ER -
ID: 276652073