用Bochner－Riesz平均逼近及Hardy求和

APPROXIMATION BY BOCHNER-RIESZ MEANS AND HARDY SUMMABILITY

设ｆ∈（Ｑ＿ｎ），ｎ∈Ｎ且Ｓ＿Ｒ￣（ｎ－１）／２（ｆ）是ｆ的临界阶Ｂｏｃｈｎｅｒ─Ｒｉｅｓｚ平均．求得了（Ｈ，ｑ）逼近的阶的估计：其中ω＿２表示二阶连续模，ｑ＞０且ｃ是常数．同时研究了这类逼近的饱和问题．

Let f∈C(Qn), n∈N and S_R￣(n-1)/2 (f) be the Bochner-Riesz means of critical order of f. Get the estimate for the degree of (H, q) approximation:where ω2 denotes the second modulus of continuity, q>0 and c is a constant. The saturation problem of this kind of approximation is also investigated.