×

Indexed absolute almost convoluted Nörlund summability. (English) Zbl 1530.40003

Suppose that \(\varphi=(\varphi_n)_{n=0}^{\infty}\) is a sequence of real numbers. Then the series \(\sum_{n=0}^{\infty}a_n\) is said to be indexed almost absolute convoluted Nörlund-summable \(\varphi\)-\(|N, p, q; m|_k\) of order \(k\geq 1\) if the series \[ \sum_{n=1}^{\infty}|\varphi_n(t_{n, m}^{p, q}-t_{n-1, m}^{p, q})|^k \] is uniformly convergent with respect to \(m\), where \(t_{n, m}^{p, q}\) is defined by \begin{align*} t_{n, m}^{p, q}&=\frac{1}{(p*q)_n}\sum_{\nu=0}^{n}p_{n-\nu}q_\nu s_{\nu, m},\\ s_{n, m}&=\frac{1}{n+1}\sum_{\nu=n}^{n+m}s_\nu,\ \text{ and } \\ (p*q)_n&=\sum_{\nu=0}^{n}p_{n-\nu}q_\nu. \end{align*} Let \(\Phi_n(x)\) be an orthonormal system. In this paper, the authors obtain some sufficient conditions under which the orthonormal series \(\sum_{n=0}^{\infty}a_n\Phi_n(x)\) is almost everywhere \(\varphi\)-\(|N, p, q; m|_k\) summable.

MSC:

40A30 Convergence and divergence of series and sequences of functions
40G05 Cesàro, Euler, Nörlund and Hausdorff methods
40F05 Absolute and strong summability
42C05 Orthogonal functions and polynomials, general theory of nontrigonometric harmonic analysis

References:

[1] H. Bor, Absolute N¨orlund summability factors.Utilitas Math.40(1991), 231-236. · Zbl 0754.40004
[2] H. Bor, On the absolute N¨orlund summability factors.Glas. Mat. Ser. III27(47) (1992), no. 1, 57-62. · Zbl 0781.40004
[3] H. Bor, A note on absolute N¨orlund summability factors.Real Anal. Exchange18(1992/93), no. 1, 82-86. · Zbl 0770.40004
[4] H. Bor, Absolute N¨orlund summability factors of infinite series.Bull. Calcutta Math. Soc.85(1993), no. 3, 223-226. · Zbl 0790.40003
[5] H. Bor, On absolute N¨orlund summability factors.Comput. Math. Appl.60(2010), no. 7, 2031-2034. · Zbl 1205.40012
[6] H. Bor, Absolute N¨orlund summability factors involving almost increasing sequences.Appl. Math. Comput.259 (2015), 828-830. · Zbl 1390.40008
[7] G. C. H. G¨ule¸c, M. A. Sarig¨ol, Hausdorff measure of noncompactness of certain matrix operators on absolute N¨orlund spaces.Trans. A. Razmadze Math. Inst.175(2021), no. 2, 205-214. · Zbl 1494.40007
[8] G. C. Hazar, M. A. Sarig¨ol, On absolute N¨orlund spaces and matrix operators.Acta Math. Sin. (Engl. Ser.)34 (2018), no. 5, 812-826. · Zbl 1404.40005
[9] G. C. Hazar, M. A. Sarig¨ol, On factor relations between weighted and N¨orlund means.Tamkang J. Math.50(2019), no. 1, 61-69. · Zbl 1427.40003
[10] Xh. Z. Krasniqi, On absolute almost generalized N¨orlund summability of orthogonal series.Kyungpook Math. J.52 (2012), no. 3, 279-290. · Zbl 1289.42019
[11] L. Leindler, On the absolute Riesz summability of orthogonal series.Acta Sci. Math. (Szeged)46(1983), no. 1-4, 203-209. · Zbl 0538.42015
[12] L. Leindler, On the newly generalized absolute Riesz summability of orthogonal series.Anal. Math.21(1995), no. 4, 285-297. · Zbl 0859.40005
[13] L. Leindler, K. Tandori, On absolute summability of orthogonal series.Acta Sci. Math. (Szeged)50(1986), no. 1-2, 99-104. · Zbl 0618.42014
[14] I. P. Natanson,Theory of Functions of a Real Variable. Vol. II. Translated from the Russian by Leo F. Boron Frederick Ungar Publishing Co., New York 1961 265 pp.
[15] Y. Okuyama, On the absolute N¨orlund summability of orthogonal series.Proc. Japan Acad. Ser. A Math. Sci.54 (1978), no. 5, 113-118. · Zbl 0409.42004
[16] Y. Okuyama, On absolute generalized N¨orlund summability of orthogonal series.Tamkang J. Math.33(2002), no. 2, 161-165. · Zbl 1017.42020
[17] Y. Okuyama, T. Tsuchikura, On the absolute Riesz summability of orthogonal series.Anal. Math.7(1981), no. 3, 199-208. · Zbl 0479.42008
[18] B. E. Rhoades, On the total inclusion for N¨orlund methods of summability.Mathematische Zeitschrift96(1971), no. 3, 183-188. · Zbl 0148.03703
[19] B. E. Rhoades, E. Sava¸s, On absolute N¨orlund summability of Fourier series.Tamkang J. Math.33(2002), no. 4, 359-364. · Zbl 1030.40005
[20] M. A. Sarig¨ol, On some absolute summability methods.Bull. Calcutta Math. Soc.83(1991), no. 5, 421-426. · Zbl 0765.40004
[21] M. A. Sarig¨ol, On|T|ksummability and absolute N¨orlund summability.Math. Slovaca42(1992), no. 3, 325-329. · Zbl 0762.40004
[22] M. A. Sarig¨ol, M. Mursaleen, Almost absolute weighted summability with indexkand matrix transformations. J. Inequal. Appl.2021, Paper no. 108, 11 pp. · Zbl 1504.40014
[23] M. Tanaka, On generalized N¨orlund methods of summability.Bull. Austral. Math. Soc.19(1978), no. 3, 381-402 · Zbl 0425.40004
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.