International Journal of Mathematics and Mathematical Sciences
Volume 2003 (2003), Issue 20, Pages 1251-1260
doi:10.1155/S0161171203204269
  
     
          
          Modulus of smoothness and theorems concerning approximation on compact groups
          
            H. Vaezi1
             and S.F. Rzaev2
          
          1Faculty of Mathematical Sciences, University of Tabriz, Tabriz, Iran
          2Institute of Mathematics and Mechanics, Azerbaijan Academy of Sciences, Baku, Azerbaijan
          
          Abstract
We consider the generalized shift operator defined by (Shuf)(g)=∫Gf(tut−1g)dt on a compact group G, and by using this operator, we define spherical modulus of smoothness. So, we prove Stechkin and Jackson-type theorems.