Spectral Semi-Invariants of Stationary Processes with Sufficiently Strong Mixing

This paper investigates one class of stochastic stationary processes which was defined in [1]. The complex semi-invariants of this class are estimated by (7). Under conditions (7), we obtain the formulae (8) and the estimate (10) for the spectral functions $f_n(\lambda_1,\dots,\lambda_n)$.