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On a result of Levin and Stečkin. (English) Zbl 1264.26026

Summary: The following inequality for \(0<p<1\) and \(a_n\geq 0\) originates from a study of G. H. Hardy, J. E. Littlewood and G. Pólya [Inequalities. Cambridge: At the University Press (1988; Zbl 0634.26008)]: \[ \sum_{n-1}^\infty \left(\frac 1n \sum_{k-n}^n a_k\right)^p\geq c_p\sum_{n-1}^\infty a_n^p. \] V. I. Levin and S. B. Stechkin [Am. Math. Soc., Transl., II. Ser 14, 1–29 (1960; Zbl 0100.04503)] proved the previous inequality with the best constant \(c_p = (p/(1-p)^p)\) for \(0 < p\leq 1/3\). In this paper, we extend the result of Levin and Stechkin to \(0 <p \leq 0.346\).

MSC:

26D15 Inequalities for sums, series and integrals

References:

[1] G. H. Hardy, J. E. Littlewood, and G. Pólya, Inequalities, Cambridge University Press, Cambridge, UK, 1952. · Zbl 0047.05302
[2] V. I. Levin and S. B. Ste\vckin, “Inequalities,” American Mathematical Society Translations, vol. 14, pp. 1-29, 1960. · Zbl 0100.04503
[3] P. Gao, “Hardy-type inequalities via auxiliary sequences,” Journal of Mathematical Analysis and Applications, vol. 343, no. 1, pp. 48-57, 2008. · Zbl 1138.26309 · doi:10.1016/j.jmaa.2008.01.024
[4] H. L. Montgomery, “The analytic principle of the large sieve,” Bulletin of the American Mathematical Society, vol. 84, no. 4, pp. 547-567, 1978. · Zbl 0408.10033 · doi:10.1090/S0002-9904-1978-14497-8
[5] K. Knopp, “Über Reihen mit positiven Gliedern,” Journal of the London Mathematical Society, vol. 3, pp. 205-211, 1928. · JFM 54.0225.01 · doi:10.1112/jlms/s1-3.3.205
[6] K. Knopp, “Über Reihen mit positiven Gliedern,” Journal of the London Mathematical Society, vol. 5, pp. 13-21, 1930. · JFM 56.0202.02 · doi:10.1112/jlms/s1-5.1.13
[7] P. Gao, “On lp norms of weighted mean matrices,” Mathematische Zeitschrift, vol. 264, no. 4, pp. 829-848, 2010. · Zbl 1190.47012 · doi:10.1007/s00209-009-0490-2
[8] G. Bennett, “Factorizing the classical inequalities,” Memoirs of the American Mathematical Society, vol. 120, no. 576, pp. 1-130, 1996. · Zbl 0857.26009
[9] P. Gao, “On weighted mean matrices whose lp norms are determined on decreasing sequences,” Mathematical Inequalities & Applications, vol. 14, pp. 373-387, 2011. · Zbl 1237.47008 · doi:10.1007/s00209-009-0490-2
[10] P. Gao, “A note on Hardy-type inequalities,” Proceedings of the American Mathematical Society, vol. 133, no. 7, pp. 1977-1984, 2005. · Zbl 1068.26015 · doi:10.1090/S0002-9939-05-07964-5
[11] P. Gao, “On lp norms of weighted mean matrices,” Mathematische Zeitschrift, vol. 264, no. 4, pp. 829-848, 2010. · Zbl 1190.47012 · doi:10.1007/s00209-009-0490-2
[12] H. Alzer, “Sharp bounds for the ratio of q-gamma functions,” Mathematische Nachrichten, vol. 222, pp. 5-14, 2001. · Zbl 0968.33004 · doi:10.1002/1522-2616(200102)222:1<5::AID-MANA5>3.0.CO;2-Q
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