𝔖 Bobbio Scriptorium
✦   LIBER   ✦

On the nonomnipotence of regular summability methods

✍ 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.

✦ 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


πŸ“œ SIMILAR VOLUMES


On Scales of Summability Methods
✍ RΓΌdiger Kiesel πŸ“‚ Article πŸ“… 1995 πŸ› John Wiley and Sons 🌐 English βš– 402 KB

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 Riemann Summability of Fourier In
✍ Ferenc MΓ³ricz πŸ“‚ Article πŸ“… 2000 πŸ› John Wiley and Sons 🌐 English βš– 213 KB πŸ‘ 2 views

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

On the Regularity of Multivariate Hermit
✍ Hakop A. Hakopian πŸ“‚ Article πŸ“… 2000 πŸ› Elsevier Science 🌐 English βš– 148 KB

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