On -convergence and -density
Ordinary convergence follows from statistical summability (C,1) in the case of slowly decreasing or oscillating sequences
Schmidt’s Tauberian theorem says that if a sequence (xk) of real numbers is slowly decreasing and , then . The notion of slow decrease includes Hardy’s two-sided as well as Landau’s one-sided Tauberian conditions as special cases. We show that ordinary summability (C,1) can be replaced by the weaker assumption of statistical summability (C,1) in Schmidt’s theorem. Two recent theorems of Fridy and Khan are also corollaries of our Theorems 1 and 2. In the Appendix, we present a new proof of Vijayaraghavan’s...
Ordre, convergence et sommabilité de produits de séries de Dirichlet
L’article donne des réponses optimales ou presque optimales aux questions suivantes, qui remontent à Stieltjes, Landau et Bohr, et concernent des séries de Dirichlet
Permutations preserving Cesàro mean, densities of natural numbers and uniform distribution of sequences
We are interested in permutations preserving certain distribution properties of sequences. In particular we consider -uniformly distributed sequences on a compact metric space , 0-1 sequences with densities, and Cesàro summable bounded sequences. It is shown that the maximal subgroups, respectively subsemigroups, of leaving any of the above spaces invariant coincide. A subgroup of these permutation groups, which can be determined explicitly, is the Lévy group . We show that is big in the...
Pointwise limit theorem for a class of unbounded operators in -spaces
We distinguish a class of unbounded operators in , r ≥ 1, related to the self-adjoint operators in ². For these operators we prove a kind of individual ergodic theorem, replacing the classical Cesàro averages by Borel summability. The result is equivalent to a version of Gaposhkin’s criterion for the a.e. convergence of operators. In the proof, the theory of martingales and interpolation in -spaces are applied.
Procédé de convergence minimale dans les espaces de Banach. Une loi des grands nombres et un théorème ergodique
Product Theorems for Certain Summability Methods in Non-archimedean Fields
In this paper, denotes a complete, non-trivially valued, non-archimedean field. Sequences and infinite matrices have entries in The main purpose of this paper is to prove some product theorems involving the methods and in such fields
Quasi -power increasing sequences.
Radon Measures on ß N Associated with Simple Riesz-Means.
Repeated convergence and fractional differences
Résurgence quantique
Section of Euler summability method.
Sobre c-dualidad y espacios c-perfectos.
Sobre sumabilidad Cesáro en el espacio CS (I).
Soma Estimates of the H...-Uniform Distribution.
Some absolutely effective product methods.
Some analogues of Knopp's core theorem.
Some generalisations on a scale of Abel type summability methods
Some inclusion theorems for absolute summability
Some properties of Riesz means and spectral expansions. (With an appendix by R. A. Gustafson).