10 citations · 15 across the 8 of their papers we have counts for
8 papers
Pink Noise in Economic Time Series from Synchronization and Amplitude Demodulation
Masahiro Morikawa, Yokoh Morikawa, Akika Nakamichi
Pink noise, characterized by a power spectral density with , appears in economic indices as well as in many natural systems. We summarize a unified mes…
A Synchronized Spin Model for Black-Hole Accretion Systems
Masahiro Morikawa, Akika Nakamichi
Black-hole accretion systems exhibit a characteristic coexistence of activities: broad-band X-ray variability, hot coronae, wide-angle winds, and both steady and discrete jets. Thi…
Pink noise in Electric Current from Amplitude Modulations
Masahiro Morikawa, Akika Nakamichi
We recently proposed that the general origin of 1/f fluctuation, or pink noise, is the amplitude modulation (or beat) of many waves with accumulating frequencies. In this paper, we…
Dynamic Synchronization and Resonance as a Universal Origin of 1/f Fluctuations -- Amplitude Modulation Across Music and Nature
Akika Nakamichi, Izumi Uesaka, Masahiro Morikawa
We propose a universal physical mechanism for the emergence of 1/f fluctuations, observed across a wide range of systems. In particular, we verify this on acoustic cases. The mecha…
Solar Flare 1/f Fluctuations from Amplitude Modulated Five Minute Oscillation
Masahiro Morikawa, Akika Nakamichi
We first study the solar flare time sequence based on the GOES16 data. We find that the power spectrum density of the low-energy (E\leq E_{mean}) flare shows 1/f fluctuations, but…
A domino model for geomagnetic field reversals
N. Mori, D. Schmitt, A. Ferriz-Mas +4
We solve the equations of motion of a one-dimensional planar Heisenberg (or Vaks-Larkin) model consisting of a system of interacting macro-spins aligned along a ring. Each spin has…