Abstract
Presenting a unified approach, we establish a Kolmogorov-type comparison theorem for classes of 2π-periodic functions defined by a special class of operators having certain oscillation properties, which include the classical Sobolev class of 2π-periodic functions, the Achieser class, and the Hardy-Sobolev class as examples. Then, using these results, we prove a Taikov-type inequality, and calculate the exact values of the Kolmogorov, Gel'fand, linear, and information n-widths of these classes of functions in the space Lq, which is the classical Lebesgue integral space of 2π-periodic functions with the usual norm.
Similar content being viewed by others
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Gensun, F., Xuehua, L. Comparison Theorems of Kolmogorov Type for Classes Defined by Cyclic Variation Diminishing Operators and Their Application. Constr Approx 27, 99–120 (2008). https://doi.org/10.1007/s00365-006-0647-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00365-006-0647-2