Pointwise multipliers on martingale Campanato spaces
We introduce generalized Campanato spaces on a probability space (Ω,ℱ,P), where p ∈ [1,∞) and ϕ: (0,1] → (0,∞). If p = 1 and ϕ ≡ 1, then . We give a characterization of the set of all pointwise multipliers on .