Abstract. We prove a general functional limit theorem for multiparameter fractional Brownian motion. The functional law of the iterated logarithm, functional Lévy's modulus of continuity and many other results are its particular cases. Applications to approximation theory are discussed.
IntroductionLet B(t) = B(t, ω), t ≥ 0, ω ∈ Ω be the Brownian motion on the probability space (Ω, F, P). The law of the iterated logarithm (Khintchin, 1924) states that P ω : lim sup t→∞ B(t, ω) √ 2t log log t = 1 = 1.We abbreviate this as(1) lim sup t→∞ B(t) √ 2t log log t = 1 P − a. s., where a. s. stands for almost surely. The functional counterpart to the law of the iterated logarithm was discovered by (Strassen, 1964). Let C[0, 1] be the Banach space of all continuous functions f : [0, 1] → R with the uniform topology generated by the maximum norm f ∞ = max t∈[0,1] |f (t)|.