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Main Authors: Hisakado, Masato, Kaneko, Takuya
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2305.12632
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author Hisakado, Masato
Kaneko, Takuya
author_facet Hisakado, Masato
Kaneko, Takuya
contents We study the eigenvalue of the Wishart matrix, which is created from a time series with temporal correlation. When there is no correlation, the eigenvalue distribution of the Wishart matrix is known as the Marchenko-Pastur distribution (MPD) in the double scaling limit. When there is temporal correlation, the eigenvalue distribution converges to the deformed MPD which has a longer tail and higher peak than the MPD. Here we discuss the moments of distribution and convergence to the deformed MPD for the Gaussian process with a temporal correlation. We show that the second moment increases as the temporal correlation increases. When the temporal correlation is the power decay, we observe a phenomenon such as a phase transition. When $γ>1/2$ which is the power index of the temporal correlation, the second moment of the distribution is finite and the largest eigenvalue is finite. On the other hand, when $γ\leq 1/2$, the second moment is infinite and the largest eigenvalue is infinite. Using finite scaling analysis, we estimate the critical exponent of the phase transition.
format Preprint
id arxiv_https___arxiv_org_abs_2305_12632
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Deformation of Marchenko-Pastur distribution for the correlated time series
Hisakado, Masato
Kaneko, Takuya
Statistical Mechanics
Statistical Finance
We study the eigenvalue of the Wishart matrix, which is created from a time series with temporal correlation. When there is no correlation, the eigenvalue distribution of the Wishart matrix is known as the Marchenko-Pastur distribution (MPD) in the double scaling limit. When there is temporal correlation, the eigenvalue distribution converges to the deformed MPD which has a longer tail and higher peak than the MPD. Here we discuss the moments of distribution and convergence to the deformed MPD for the Gaussian process with a temporal correlation. We show that the second moment increases as the temporal correlation increases. When the temporal correlation is the power decay, we observe a phenomenon such as a phase transition. When $γ>1/2$ which is the power index of the temporal correlation, the second moment of the distribution is finite and the largest eigenvalue is finite. On the other hand, when $γ\leq 1/2$, the second moment is infinite and the largest eigenvalue is infinite. Using finite scaling analysis, we estimate the critical exponent of the phase transition.
title Deformation of Marchenko-Pastur distribution for the correlated time series
topic Statistical Mechanics
Statistical Finance
url https://arxiv.org/abs/2305.12632