Abstract
The main purpose of the paper is to study sharp estimates of approximation of periodic functions in the Hölder spaces Hpr,α for all 0 < p≤ ∞ and 0 < α ≤ r. By using modifications of the classical moduli of smoothness, we give improvements of the direct and inverse theorems of approximation and prove the criteria for the precise order of decrease of the best approximation in these spaces. Moreover, we obtained strong converse inequalities for general methods of approximation of periodic functions in Hpr,α.
| Original language | English |
|---|---|
| Journal | Journal of Approximation Theory |
| Volume | 200 |
| Pages (from-to) | 68-91 |
| Number of pages | 24 |
| ISSN | 0021-9045 |
| DOIs | |
| Publication status | Published - 01.12.2015 |
Funding
The authors are indebted to the referees for a thorough reading and valuable suggestions, which allowed them to improve this paper considerably. The authors were supported by FP7-People-2011-IRSES Project number 295164 (EUMLS: EU-Ukrainian Mathematicians for Life Sciences). The first author was supported by the Grant of the National Academy of Sciences of Ukraine for young scientists.