Abel extensions of some classical Tauberian theorems

2019 ◽  
Vol 28 (2) ◽  
pp. 105-112
Author(s):  
ERDAL GUL ◽  
MEHMET ALBAYRAK

The well-known classical Tauberian theorems given for Aλ (the discrete Abel mean) by Armitage and Maddox in [Armitage, H. D and Maddox, J. I., Discrete Abel means, Analysis, 10 (1990), 177–186] is generalized. Similarly the ”one-sided” Tauberian theorems of Landau and Schmidt for the Abel method are extended by replacing lim As with Abel-lim Aσi n(s). Slowly oscillating of {sn} is a Tauberian condition of the Hardy-Littlewood Tauberian theorem for Borel summability which is also given by replacing limt(Bs)t = `, where t is a continuous parameter, with limn(Bs)n = `, and further replacing it by Abel-lim(Bσi k (s))n = `, where B is the Borel matrix method.

1992 ◽  
Vol 44 (5) ◽  
pp. 1100-1120 ◽  
Author(s):  
Laying Tam

AbstractOur main result is a Tauberian theorem for the general Euler-Borel summability method. Examples of the method include the discrete Borel, Euler, Meyer- Kônig, Taylor and Karamata methods. Every function/ analytic on the closed unit disk and satisfying some general conditions generates such a method, denoted by (£,ƒ). For instance the function ƒ(z) = exp(z — 1) generates the discrete Borel method. To each such function ƒ corresponds an even positive integer p = p(f).We show that if a sequence (sn)is summable (E,f)and as n→ ∞ m > n, (m— n)n-p(f)→0, then (sn)is convergent. If the Maclaurin coefficients of/ are nonnegative, then p(f) =2. In this case we may replace the condition . This generalizes the Tauberian theorems for Borel summability due to Hardy and Littlewood, and R. Schmidt. We have also found new examples of the method and proved that the exponent —p(f)in the Tauberian condition (*) is the best possible.


1993 ◽  
Vol 47 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Jeff Connor

In the first section we establish a connection between gap Tauberian conditions and isomorphic copies of Co for perfect coregular conservative BK spaces and in the second we give a characterisation of gap Tauberian conditions for strong summability with respect to a nonnnegative regular summability matrix. These results are used to show that a gap Tauberian condition for strong weighted mean summability is also a gap Tauberian condition for ordinary weighted mean summability. We also make a remark regarding the support set of a matrix and give a Tauberian theorem for a class of conull spaces.


1980 ◽  
Vol 3 (4) ◽  
pp. 731-738 ◽  
Author(s):  
J. A. Fridy ◽  
K. L. Roberts

The well-known summability methods of Euler and Borel are studied as mappings fromℓ1intoℓ1. In thisℓ−ℓsetting, the following Tauberian results are proved: ifxis a sequence that is mapped intoℓ1by the Euler-Knopp methodErwithr>0(or the Borel matrix method) andxsatisfies∑n=0∞|xn−xn+1|n<∞, thenxitself is inℓ1.


Author(s):  
Ümit Totur

Abstract In this paper we generalize some classical Tauberian theorems for single sequences to double sequences. One-sided Tauberian theorem and generalized Littlewood theorem for (C; 1; 1) summability method are given as corollaries of the main results. Mathematics Subject Classification 2010: 40E05, 40G0


2021 ◽  
pp. 84
Author(s):  
T.N. Yarkovaia

We establish a Tauberian theorem in the case of strong summability in degree $p$ of double series by matrix methods, give its application to Abel methods.


1997 ◽  
Vol 11 (18) ◽  
pp. 2157-2182 ◽  
Author(s):  
Kazumoto Iguchi

In this paper we discuss the application of the Saxon–Hutner theorem and its converse theorem in one-dimensional binary disordered lattices to the one-dimensional binary quasiperiodic lattices. We first summarize some basic theorems in one-dimensional periodic lattices. We discuss how the bulk and edge states are treated in the transfer matrix method. Second, we review the Saxon–Hutner theorem and prove the converse theorem, using the so-called Fricke identities. Third, we present an alternative approach for a rigorous proof of the existence of a Cantor-set spectrum in the Fibonacci lattice and in the related binary quasiperiodic lattices by means of the theorems together with their trace map with the invariant I. We obtain that if I > 0, then the spectrum is always a Cantor set, which was first proved for the Fibonacci lattice by Sütö and generalized for other quasiperiodic lattices by Bellissard, Iochum, Scopolla, and Testard. Fourth, we rigorously prove the existence of extended states in the spectrum of a class of binary quasiperiodic lattices first studied by Kolář and Ali. Fifth, we discuss the so-called gap labeling theorem emphasized by Bellissard and the classic argument of Kohn and Thouless for localized states in a one-dimensional disordered lattice in terms of the language of the transfer matrix method.


1963 ◽  
Vol 15 ◽  
pp. 433-439
Author(s):  
Ralph Henstock

When, for the generalized summation of series, we use A and B methods, giving A and B sums, respectively, we say that the A method is included in the B method, A ⊂ B, if the B sum exists and is equal to the A sum whenever the latter exists. A theorem proving such a result is called an Abelian theorem. For example, there is an Abelian theorem stating that if the A and B sums are the first Cesàro mean and the Abel mean, respectively, then A ⊂ B. If A ⊂ B and B ⊂ A, we say that A and B are equivalent, A = B. For example, the nth Hölder and nth. Cesàro means are equivalent.


Sign in / Sign up

Export Citation Format

Share Document