EN
By a harmonizable sequence of random variables we mean the sequence of Fourier coefficients of a random measure M:
$Xₙ(M) = ∫_{0}^{1} e^{2πnis}M(ds)$ (n = 0,±1,...)
The paper deals with prediction problems for sequences {Xₙ(M)} for isotropic and atomless random measures M. The crucial result asserts that the space of all complex-valued M-integrable functions on the unit interval is a Musielak-Orlicz space. Hence it follows that the problem for {Xₙ(M)} (n = 0,±1,...) to be deterministic is in fact an extremal problem of Szegö's type for Musielak-Orlicz spaces in question. This leads to a characterization of deterministic sequences {Xₙ(M)} (n = 0,±1,...) in terms of random measures M.