## Abstract The boundedness of singular convolution operators __f__ ↦ __k__ ∗︁ __f__ is studied on Besov spaces of vector‐valued functions, the kernel __k__ taking values in ℒ︁(__X__ , __Y__ ). The main result is a Hörmander‐type theorem giving sufficient conditions for the boundedness of such an
On Some Singular Integrals in Hölder Spaces
✍ Scribed by B. Firlejy; L. Rempulska
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 222 KB
- Volume
- 170
- Category
- Article
- ISSN
- 0025-584X
No coin nor oath required. For personal study only.
✦ Synopsis
The approximation of functions by singular integrals is an important question in the theory of differential and integral equations. Therefore the consideration of approximation problems in various norms is useful.
Recently in many papers approximation problems have been studied in the Holder norms
In [2] the orders of approximation are obtained for the Picard, Poisson-Cauchy and GauD-WeierstraD singular integrals in the supremum norm and the classical Holder norm. In [3] error estimates for the Fourier sum and the trigonometric interpolatory polynomial are given in generalized Holder norms.
Using notations given in [2] and [3], we present in this paper approximation theorems for the singular integrals [2] in some generalized Holder norms. Those theorems contain and improve the results obtained in [2].
📜 SIMILAR VOLUMES
Math. Nechr. 149 (1990) and (1.7) respectively, where the parameter 5 tends to 0. n W Z , 5 ) = ( 6 Z -l J I(% + 1) exp (-t2/5) d t , -JI Throughout the paper, we shall write (1.8) @A = I(% + 1) -2f(Z)'+ f ( Z -0 . 2.
The classical polynomial collocation method is considered for a class of Cauchy singular integral equations with variable coefficients on a bounded interval. This method is naturally extended to the case of a non-zero index of the underlying Fredholm operator. This is done by using the structure of
## Abstract We discuss some reversed Hölder inequalities yielding for functions on R~+~ satisfying one or two conditions of quasi‐monotonicity. All cases of equality are pointed out. By using these results and some recent results by the present authors (see [3]), we prove some new reversed inequali