摘要
本文得到了二元周期可微函数类△_p^r在空间L_q(T^2)中的正交投影宽度d1/N(△_p^r,L_q)的渐近精确阶.
The following asymptotic order of orthowidths d1/N(△^rp, Lq) of class of functions 1 in the metric Lq(T^2) is obtained for 1 〈p,q 〈 ∞ and r 〉 (1/p -1/q)+:d1/N(△^rp ,Lq)=N^-r+(1/p-1/q)+and the Fourier partial sum Snn (f) (n=√N) is an asymptotic optimal orthogonal projection operator.
出处
《数学进展》
CSCD
北大核心
2006年第5期629-634,共6页
Advances in Mathematics(China)