On approximation methods generated by generalized Bochner-Riesz kernels
  Some sharp results related to the convergence of means and families of operators generated by the generalized Bochner-Riesz kernels are obtained. The exact order of approximation of functions by these methods via $K$-functional (or its realization in the case of the space $L_p$, $0<p<1$) is derived. 
Yurii Kolomoitsev
math.CA math.FA