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From the 1 of 5 linked papers with an AI index.

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20242026
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5 papers

cond-mat.stat-mech2026

Deformation of semi-circle law for the correlated time series and Phase transition

Masato Hisakado, Takuya Kaneko

The paper analyzes random matrices built from temporally correlated financial time series, showing how the eigenvalue distribution deviates from the classic semicircle law and iden…

cond-mat.stat-mech2026

A Cascade of Volterra-Operator BBP Transitions in a Correlated Wigner Matrix

Masato Hisakado

We study a Wigner-type random matrix in which the off-diagonal correlation between entries is generated by a random factor shared among all entries in a given row and column, with…

q-fin.RM2026

Temporal Coarse-Graining of Multi-Sector Default Count Data Generates Posterior-Implied Copulas

Shintaro Mori, Masato Hisakado

Sectoral default dependence is usually described by a static correlation matrix, a static copula, or a small number of common factors. Such representations, when specified separate…

q-fin.RM2025

Phase transition in a long-memory log-Gaussian Cox process

Masato Hisakado, Shintaro Mori

We study a stochastic point process with power-law temporal correlations driven by hidden variables. We show that a generalized Merton-type model under an exponential-tail asset as…

cond-mat.stat-mech2024

Deformation of Marchenko-Pastur distribution for the correlated time series

Masato Hisakado, Takuya Kaneko

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 Wisha…