On the relations among best approximation and Fourier coeffcients  

作　　者：YU DanSheng1,2, ZHOU Ping2 & ZHOU SongPing1 1 Institute of Mathematics, Zhejiang Sci-Tech University, Hangzhou 310018, China 2 Department of Mathematics, Statistics and Computer Science, St. Francis Xavier University, Antigonish, Nova Scotia, Canada, B2G 2W5 

出　　处：《Science China Mathematics》2008年第10期1883-1894,共12页中国科学：数学（英文版）

基　　金：NSERC RCD grant and AARMS of Canada (Yu D S);by NSERC of Canada(Zhou P);by the National Natural Science Foundation of China (Grant No. 10471130);the Open Fund(Grant No. PLN0613) of State Key Laboratory of Oil;Gas Reservoir Geology and Exploitation (Southwest Petroleum University) (Zhou S P)

摘　　要：We discuss the relations among the best approximation En(f) and the Fourier coeffcients of a function, f(n) ∈ C,n = 0,±1,±2,..., under the conditions that {f (n)}∞n=0 ∈ MVBVS* and {f (n) + f(n)}∞n=0 ∈ MVBVS*, where MVBVS* is the class of the so-called Strong Mean Value Bounded Variation Sequences.We discuss the relations among the best approximation En(f) and the Fourier coeffcients of a function, f(n) ∈ C,n = 0,±1,±2,..., under the conditions that {f (n)}∞n=0 ∈ MVBVS* and {f (n) + f(n)}∞n=0 ∈ MVBVS*, where MVBVS* is the class of the so-called Strong Mean Value Bounded Variation Sequences.

关 键 词：best APPROXIMATION FOURIER coeffcients mean value BOUNDED VARIATION 

分 类 号：O174.41[理学—数学]