Approximation in Bounded Summability Fields

1968 ◽  
Vol 20 ◽  
pp. 410-415 ◽  
Author(s):  
J. D. Hill ◽  
W. T. Sledd

This paper deals with several related properties of bounded summability fields of regular, real matrices. For a matrix A = (ank) and a sequence x = {xn}, we write formallyWe denote by m the space of bounded real sequences, and by A* the bounded summability fieldof A. The strong summability field of A is the set

1959 ◽  
Vol 11 ◽  
pp. 48-50 ◽  
Author(s):  
Martin Pearl

In a recent paper (3)* the following theorem was proved for real matrices.Theorem 1. If A is a symmetric matrix and Q is a skew-symmetric matrix such that A + Q is non-singular, then1is a cogredient automorph (c.a.) of A whose determinant is + 1 and having theproperty that A and I + P span the same row space.Conversely, if P is a c.a. of A whose determinant is + 1 and if P has theproperty that I + P and A span the same row space, then there exists a skew symmetricmatrix Q such that P is given by equation (1).Theorem 1 reduces to the well-known Cayley parameterization in the case where A is non-singular. A similar and somewhat simpler result (Theorem 4) was given for the case when the underlying field is the complex field. It was also shown that the second part of the theorem (in either form) is false when the characteristic of the underlying field is 2. The purpose of this paper is to simplify the proof of Theorem 1 and at the same time, to extend these results to matrices over an arbitrary field of characteristic ≠ 2.


Author(s):  
C. S. Chun ◽  
A. R. Freedman

The study of R-type summability methods is continued in this paper by showing that two such methods are identical on the bounded portion of the strong summability field associated with the methods. It is shown that this “bounded consistency” applies for many non-matrix methods as well as for regular matrix methods.


1967 ◽  
Vol 63 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Babban Prasad Mishra

Introduction. In a recent paper, Borwein(1) constructed a new method of summability which would read: Letand let {sn} be any sequence of numbers. If, for λ > − 1,is convergent for all x in the open interval (0,1) and tends to a finite limit s as x → 1 in (0,1), we say that the sequence {sn} is Aλ convergent to s and write sn → s(Aλ). The A0 method is the ordinary Abel method.


1930 ◽  
Vol 26 (4) ◽  
pp. 429-437 ◽  
Author(s):  
R. E. A. C. Paley

Let f(t) be a function periodic in 2π, and absolutely integrable in the interval (0, 2π). We write


1953 ◽  
Vol 9 (1) ◽  
pp. 28-34
Author(s):  
C. F. Harington ◽  
J. M. Hyslop

Given a series Σan, we define , by the relationwhere is the binomial coefficient . Let . If , the series Σan is said to be summable (C; k) to the sum s. If k > 0, p ≥ 1 and if, as n → ∞,we say that the series Σan is summable [C; k, p] to the sum s, or that the series is strongly summable (C; k) with index p to the sum s. If denotes the difference , it is known that necessary and sufficient conditions for summability [C; k, p], k > 0, p ≥ 1, to the sum s, are that Σan be summable (C; k) to the sum s and that


1986 ◽  
Vol 99 (3) ◽  
pp. 507-518
Author(s):  
Seppo Hyydö ◽  
Jorma Kaarlo Merikoski ◽  
Ari Virtanen

Throughout this paper we let A = (aij) be a non-zero n × n matrix-we study real matrices only–with row sums R1,…Rn and eigenvalues λ1,…,λn, ordered λ1≥…≥λn if they are real. We denote E = (1,…,1)T and su A = ΣiΣjaij = ETAE. If A is symmetric, a simple property of the Rayleigh quotient is thatsatisfiesand


1980 ◽  
Vol 87 (2) ◽  
pp. 243-248
Author(s):  
I. J. Maddox

It was recently shown in (1), corollary 1, that if (I) = (N, q) then I and (N, q) were consistent. By I we denote the unit infinite matrix, and (N, q) denotes a general complex Nörlund mean. The summability field (A) of any infinite matrix A = (ank) is defined aswhere c is the space of convergent sequences. The summability field of (N, q) is, for simplicity, written as (N, q) instead of ((N, q)).


1952 ◽  
Vol 1 (1) ◽  
pp. 16-20 ◽  
Author(s):  
J. M. Hyslop

Given the series ,the n-th Casáro sum of order k is defined by the relationwhere is the binomial coefficient . Let Then Σan is said to be summable (C; K) to the sum s if, as n → ∞, The series is said to be absolutely summable (C; k), or summable | is convergent. The series is said to be strongly summable (C; k) with index p, or summable [Ck, p], to the sum s ifIt is assumed that k and p are positive.


Author(s):  
Carolyn Nohr ◽  
Ann Ayres

Texts on electron diffraction recommend that the camera constant of the electron microscope be determine d by calibration with a standard crystalline specimen, using the equation


Author(s):  
Kin Lam

The energy of moving ions in solid is dependent on the electronic density as well as the atomic structural properties of the target material. These factors contribute to the observable effects in polycrystalline material using the scanning ion microscope. Here we outline a method to investigate the dependence of low velocity proton stopping on interatomic distances and orientations.The interaction of charged particles with atoms in the frame work of the Fermi gas model was proposed by Lindhard. For a system of atoms, the electronic Lindhard stopping power can be generalized to the formwhere the stopping power function is defined as


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