In this paper we consider generalized Norlund methods (Nap), a > -1, power series methods (J,) and the iteration product of two such methods. A particular case is that of the Cesaro means (C,) with corresponding power series method (A), i.e., Abel's method. We obtain generalizations of inclusion, an
On the nonomnipotence of regular summability methods
β Scribed by S Haber; O Shisha
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 74 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0001-8708
No coin nor oath required. For personal study only.
β¦ Synopsis
Let T = (tm,J (m, n = I, 2 ,...; all t,,, , > 0) define a regular summability method. It is known [l] that there is a bounded divergent sequence whose T-transform is also divergent. Here we point out that one can say more: namely, that for some real, bounded, divergent sequence {a,}~=, , its T-transform diverges just a badly as itself. For every real sequence (a,}Ei , its T-transform {b,}~=, satisfies [2], so that, if {a,} is bounded, and, thus, the divergence of (blE} is not worse than that of (a,}. Our goal is a real, bounded, divergent sequence {a,> for which equality holds in (*). As such a sequence one can take the sequence, consisting of l's and -l's, defined in [l], as the argument given there does, in fact, establish the desired properties.
If the t,., are not assumed 20, but only real, matters are a bit worse. Inequality (*) is replaced by where
π SIMILAR VOLUMES
We consider the Riemann means of single and multiple Fourier integrals of functions belonging to L 1 or the real Hardy spaces defined on IR n , where n β₯ 1 is an integer. We prove that the maximal Riemann operator is bounded both from H 1 (IR) into L 1 (IR) and from L 1 (IR) into weak -L 1 (IR). We
In this paper a result due to Gevorgian, Sahakian, and the author concerning the regularity of bivariate Hermite interpolation is generalized in two directions: in the bivariate case and for arbitrary dimensions. Also a notion of independence (preregularity) of interpolation conditions is discussed