Equivalent Normings of Spaces of Functions of Variable Smoothness
Equivalent Normings of Spaces of Functions of Variable Smoothness
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作者:
O. V. Besov
For the Banach spaces B p,q and F a p,q of functions defined on R whose variable smoothness a = a(x) is determined by the behavior of their differences, equivalent normings are established in terms of weighted norms of smooth dyadic decompositions of their Fourier transforms. In this paper, we study the Banach spaces Ba p,q and F a p,q, 1 < p, q < ∞, of functions defined on the n-dimensional Euclidean space Rn. The smoothness properties of functions are determined by the finiteness of the weighted integral norms of their differences considered as functions of a point x ∈ Rn and the difference step. Namely, for 1 < p, q < ∞, we consider the spaces B p,q = { u : u∈Lp(R, loc), ‖u|B p,q‖= [ ∞ ∑ k=1 sup |h|≤1 ‖ak∆(2h)u|Lp(R)‖ ] 1 q + ‖a0u|Lp(R)‖<∞ } ,