Some remarks on strong approximation by Cesàro means
Some Tauberian theorems for Euler and Borel summability.
Some Tauberian Theorems for the Circle Family of Summability Methods.
Some Tauberian theorems on summability methods of integrals
Sommation effective d’une somme de Borel par séries de factorielles
Nous abordons dans cet article la question de la sommation effective d’une somme de Borel d’une série par la série de factorielles associée. Notre approche fournit un contrôle de l’erreur entre la somme de Borel recherchée et les sommes partielles de la série de factorielles. Nous généralisons ensuite cette méthode au cadre des séries de puissances fractionnaires, après avoir démontré un analogue d’un théorème de Nevanlinna de sommation de Borel fine pour ce cadre.
Spaces not distinguishing pointwise and -quasinormal convergence
In this paper we extend the notion of quasinormal convergence via ideals and consider the notion of -quasinormal convergence. We then introduce the notion of space as a topological space in which every sequence of continuous real valued functions pointwise converging to , is also -quasinormally convergent to (has a subsequence which is -quasinormally convergent to ) and make certain observations on those spaces.
Spectral decompositions, ergodic averages, and the Hilbert transform
Let U be a trigonometrically well-bounded operator on a Banach space , and denote by the sequence of (C,2) weighted discrete ergodic averages of U, that is, . We show that this sequence of weighted ergodic averages converges in the strong operator topology to an idempotent operator whose range is x ∈ : Ux = x, and whose null space is the closure of (I - U). This result expands the scope of the traditional Ergodic Theorem, and thereby serves as a link between Banach space spectral theory and...
Spectral Riesz-Cesàro means: How the square root function helps us to see around the world.
Statistical convergence of Walsh-Fourier series.
Statistical extensions of some classical Tauberian theorems in nondiscrete setting
Schmidt’s classical Tauberian theorem says that if a sequence of real numbers is summable (C,1) to a finite limit and slowly decreasing, then it converges to the same limit. In this paper, we prove a nondiscrete version of Schmidt’s theorem in the setting of statistical summability (C,1) of real-valued functions that are slowly decreasing on ℝ ₊. We prove another Tauberian theorem in the case of complex-valued functions that are slowly oscillating on ℝ ₊. In the proofs we make use of two nondiscrete...
Statistically strongly regular matrices and some core theorems.
Statistically -multiplicative matrices and some inequalities
Stokes phenomenon, multisummability and differential Galois groups
We precise the cohomological analysis of the Stokes phenomenon for linear differential systems due to Malgrange and Sibuya by making a rigid natural choice of a unique cocycle (called a Stokes cocyle) in every cohomological class. And we detail an algebraic algorithm to reduce any cocycle to its cohomologous Stokes form. This gives rise to an almost algebraic definition of sums for formal solutions of systems which we compare to the most usual ones. We also use this construction to the Stokes cocycle...
Strong convergence.
Strong laws and summability for sequences of -mixing random variables in Banach spaces.
Summability Factors for Lower-Semi-Matrix Transformations.
Summability of double sequences by weighted mean methods and Tauberian conditions for convergence in Pringsheim's sense.
Summation of polyparametrical functional series by the method of finite hybrid integral transforms (Fourier, Bessel)
Summation processes viewed from the Fourier properties of continuous unimodular functions on the circle
The main purpose of this article is to give a new method and new results on a very old topic: the comparison of the Riemann processes of summation (R,κ) with other summation processes. The motivation comes from the study of continuous unimodular functions on the circle, their Fourier series and their winding numbers. My oral presentation in Poznań at the JM-100 conference exposed the ways by which this study was developed since the fundamental work of Brézis and Nirenberg on the topological degree...
Summationsmethoden und Momentfolgen I.