Analysis of clusters formed by the moving average of a long-range correlated time series

Abstract
We analyze the stochastic function Cn(i)y(i)yn(i), where y(i) is a long-range correlated time series of length Nmax and yn(i)(1/n)k=0n1y(ik) is the moving average with window n. We argue that Cn(i) generates a stationary sequence of self-affine clusters C with length l, lifetime τ, and area s. The length and the area are related to the lifetime by the relationships lτψl and sτψs, where ψl=1 and ψs=1+H. We also find that l, τ, and s are power law distributed with exponents depending on H: P(l)lα, P(τ)τβ, and P(s)sγ, with α=β=2H and γ=2/(1+H). These predictions are tested by extensive simulations on series generated by the midpoint displacement algorithm of assigned Hurst exponent H (ranging from 0.05 to 0.95) of length up to Nmax=221 and n up to 213.