The degree of approximation by positive operators on compact connected abelian groups

Journal of the Australian Mathematical Society

Walter R. Bloom¹ 

[1] Joseph F. Sussich

关键词: primary 41 A 65;    41 A 25;    secondary 41 A 36;    43 A 70;   

DOI  :  10.1017/S1446788700018796

学科分类：数学（综合）

来源: Cambridge University Press

【 摘 要 】

In 1953 P. P. Korovkin proved that if (Tn) is a sequence of positive linear operators defined on the space C of continuous real 2 π-periodic functions and lim Tnf = f uniformly for f = 1, cos and sin, then lim Tnf = f uniformly for all f ∈ C. Quantitative versions of this result have been given, where the rate of convergence is given in terms of that of the test functions 1, cos and sin, and the modulus of continuity of f. We extend this result by giving a quantitative version of Korovkin's theorem for compact connected abelian groups.

【 授权许可】

Unknown