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An Inclusion Theorem for Bohr-Hardy Summability Factors

Published online by Cambridge University Press:  20 November 2018

B. Thorpe*
Affiliation:
University of Birmingham, Birmingham, England University of Western Ontario, London, Ontario
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1. Let A denote a sequence to sequence transformation given by the normal matrix A = (ank)(n, k = 0, 1, 2, …), i.e., a lower triangular matrix with ann ≠ 0 for all n. For B = (bnk) we write BA if every B limitable sequence is A limitable to the same limit, and say that B is equivalent to A if B ⇒ A and AB. If B is normal, then it is well known that the inverse of B exists (we denote it by B-l) and that BA if and only if F = AB-1 is a regular transformation, i.e., transforms every convergent sequence into a sequence converging to the same limit. We say that a series ∑ an† is summable A if its sequence of partial sums is A-limitable.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1971

References

1. Bohr, H., Sur la série de Dirichlet, Comptes Rendus 148 (1909) 7580.Google Scholar
2. Bosanquet, L. S., Note on the Bohr-Hardy Theorem, J. London Math. Soc. 17 (1942) 166173.Google Scholar
3. Hahn, H., Uber Folgen linearer operationen, Monatsch. fur Math, und Phys. 82 (1922) 388.Google Scholar
4. Hardy, G. H., Generalisation of a theorem in the theory of divergent series, Proc. London Math. Soc. (2) 6 (1908) 255264.Google Scholar
5. Knopp, K. and Lorentz, G. G., Betrâge zur absoluten Limitierung, Arch. Math. 2 (1949) 1016.Google Scholar
6. Jurkat, W. and Peyerimhoff, A., Mittelwertsàtze bei Matrix und Integraltransformationen, Math. Z. 55 (1951) 92108.Google Scholar
7. Jurkat, W. and Peyerimhoff, A., Summierbarkeitsfaktoren, Math. Z. 58 (1953) 186203.Google Scholar
8. Jurkat, W. and Peyerimhoff, A., Über Sàtze vom Bohr-Hardyschen Typ, Töhoku Math. J. (2) 17 (1965), 5571.Google Scholar
9. Peyerimhoff, A., Lectures on Summability, Lecture Notes in Mathematics No. 107 (Springer- Verlag, Berlin, 1969).Google Scholar
10. Vermes, P., The transpose of a summability matrix, Colloque sur la Théorie des Suites, Centre Belge de recherches Math. (1958), 6086.Google Scholar