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A note on random signs

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Abstract

Let ε, ε1, ε2, . . . be independent identically distributed Rademacher random variables, P{ε = ± 1} = 1/2. Denote S = ∑ i = 1 a i ε i , where a1, a2, . . . is a (weight) sequence of nonrandom real numbers such that ∑ i = 1 a 2 i  ≤ 1. We prove that \( \mathrm{P}\left\{S\ge x\right\}\le 1/4+\left(1-\sqrt{2-2/{x}^2}\right)/8 \) for \( x\in \left(1,\sqrt{2}\right] \).

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References

  1. A. Ben-Tal and A. Nemirovski, On safe tractable approximations of chance-constrained linear matrix inequalities, Math. Oper. Res., 34(1):1–25, 2009.

    Article  MATH  MathSciNet  Google Scholar 

  2. A. Ben-Tal, A. Nemirovski, and C. Roos, Robust solutions of uncertain quadratic and conic-quadratic problems, SIAM J. Optim., 13(2):535–560, 2002.

    Article  MATH  MathSciNet  Google Scholar 

  3. V.Yu. Bentkus, On large deviations in Banach spaces, Teor. Veroyatn. Primen., 31(4):710–716, 1986 (in Russian).

    MATH  MathSciNet  Google Scholar 

  4. V. Bentkus, An inequality for large deviation probabilities of sums of bounded i.i.d. random variables, Lith. Math. J., 41(2):112–119, 2001.

    Article  MathSciNet  Google Scholar 

  5. V. Bentkus, An inequality for tail probabilities of martingales with bounded differences, Lith. Math. J., 42(3):255–261, 2002.

    Article  MATH  MathSciNet  Google Scholar 

  6. V. Bentkus, On measure concentration for separately Lipschitz functions in product spaces, Isr. J. Math., 158:1–17, 2007.

    Article  MATH  MathSciNet  Google Scholar 

  7. V. Bentkus and D. Dzindzalieta, A tight Gaussian bound for weighted sums of Rademacher random variables, Bernoulli, 2014 (forthcomming).

  8. V. Bentkus and T. Juškeviˇcius, Bounds for tail probabilities of martingales using skewness and kurtosis, Lith. Math. J., 48(1):30–37, 2008.

    Article  MATH  MathSciNet  Google Scholar 

  9. K. Derinkuyu and M.C. Pınar, On the S-procedure and some variants, Math. Methods Oper. Res., 64(1):55–77, 2006.

    Article  MATH  MathSciNet  Google Scholar 

  10. K. Derinkuyu, M.C. Pınar, and A. Camcı, An improved probability bound for the approximate S-Lemma, Oper. Res. Lett., 35(6):743–746, 2007.

    Article  MATH  MathSciNet  Google Scholar 

  11. B. Efron, Student’s t-test under symmetry conditions, J. Am. Stat. Assoc., 64(328):1278–1302, 1969.

    MATH  MathSciNet  Google Scholar 

  12. R.K. Guy, Any answers anent these analytical enigmas?, Am. Math. Mon., 93(4):279–281, 1986.

    Article  MathSciNet  Google Scholar 

  13. S. He, Z.-Q. Luo, J. Nie, and S. Zhang, Semidefinite relaxation bounds for indefinite homogeneous quadratic optimization, SIAM J. Optim., 19(2):503–523, 2008.

    Article  MATH  MathSciNet  Google Scholar 

  14. J.-B. Hiriart-Urruty, A new series of conjectures and open questions in optimization and matrix analysis, ESAIM, Control Optim. Calc. Var., 15(2):454–470, 2009.

    Article  MATH  MathSciNet  Google Scholar 

  15. W. Hoeffding, Probability inequalities for sums of bounded random variables, J. Am. Stat. Assoc., 58:13–30, 1963.

    Article  MATH  MathSciNet  Google Scholar 

  16. R. Holzman and D.J. Kleitman, On the product of sign vectors and unit vectors, Combinatorica, 12(3):303–316, 1992.

    Article  MATH  MathSciNet  Google Scholar 

  17. A. Nemirovski, Sums of random symmetric matrices and quadratic optimization under orthogonality constraints, Math. Program., Ser. B, 109(2–3):283–317, 2007.

    Article  MATH  MathSciNet  Google Scholar 

  18. A.M.-C. So, Improved approximation bound for quadratic optimization problems with orthogonality constraints, in Proceedings of the 20th Annual ACM-SIAM Symposium on Discrete Algorithms (New York, January 4–6, 2009), SIAM, Philadelphia, PA, 2009, pp. 1201–1209.

  19. I. Tyurin, New estimates of the convergence rate in the Lyapunov theorem, preprint, 2009, arXiv:0912.0726.

  20. A.V. Zhubr, On one extremal problem for n-cube, Tr. Komi Nauchn. Tsentra UrO Ross. AN, 2(10):4–11, 2012 (in Russian).

    Google Scholar 

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Correspondence to Dainius Dzindzalieta.

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*This research was funded by a grant (No. MIP-053/2012) from the Research Council of Lithuania.

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Dzindzalieta, D. A note on random signs . Lith Math J 54, 403–408 (2014). https://doi.org/10.1007/s10986-014-9252-x

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  • DOI: https://doi.org/10.1007/s10986-014-9252-x

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