Hostname: page-component-7479d7b7d-pfhbr Total loading time: 0 Render date: 2024-07-13T13:04:48.382Z Has data issue: false hasContentIssue false

A Note on Logarithmic Summability (L)

Published online by Cambridge University Press:  20 January 2009

Y. Sitaraman
Affiliation:
Ramanujan Institute of Mathematics, University of Madras, Madras-5, India
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

It is well known that two mutually related summability methods for a sequence sn(n = 0, 1, 2, …) are any Cesaro method (C, γ) of order γ > 0 and the Abel method (A). The notation used in this statement is that of Hardy ((1), pp. 96-7, 71) and the statement itself can be amplified as follows. Summability (C, γ), γ > 0, of sn implies (i) sn = o(nγ), (ii) summability (A) of sn. Also, as a conditional converse of this result, we have Offord's result ((3), first part of Theorem 2), that hypothesis (i), and hypothesis (ii) suitably strengthened, together imply summability (C, γ), γ > 0, of sn. It is the object of this note to bring to light a second pair of summability methods mutually related like the methods (C, γ) and (A), by following an argument which is essentially similar to Offord's but differs sufficiently from Offord's in details to justify a separate and self-contained treatment of the second pair of methods.

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 1966

References

REFERENCES

(1)Hardy, G. H.Divergent Series (Oxford, 1949).Google Scholar
(2)Ishiguro, K.On the summability methods of logarithmic type, Proc. Japan Acad., 38 (1962), 703705Google Scholar
(3)Offord, A. C.On the summability of power series, Proc. London Math. Soc. (2), 33 (1932), 467480CrossRefGoogle Scholar
(4)Rangachari, M. S. and Sitaraman, Y., Tauberian theorems for logarithmic summability (L), Tôhoku Math. J. (2), 16 (1964), 257269.CrossRefGoogle Scholar