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COMPARISON OF WEAK AND STRONG MOMENTS FOR VECTORS WITH INDEPENDENT COORDINATES

Published online by Cambridge University Press:  14 February 2018

Rafał Latała
Affiliation:
Institute of Mathematics, University of Warsaw, Banacha 2, 02–097 Warsaw, Poland email rlatala@mimuw.edu.pl
Marta Strzelecka
Affiliation:
Institute of Mathematics, University of Warsaw, Banacha 2, 02–097 Warsaw, Poland email martast@mimuw.edu.pl
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Abstract

We show that for $p\geqslant 1$, the $p$th moment of suprema of linear combinations of independent centered random variables are comparable with the sum of the first moment and the weak $p$th moment provided that $2q$th and $q$th integral moments of these variables are comparable for all $q\geqslant 2$. The latest condition turns out to be necessary in the independent and identically distributed case.

Type
Research Article
Copyright
Copyright © University College London 2018 

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References

Adamczak, R., Latała, R., Litvak, A. E., Oleszkiewicz, K., Pajor, A. and Tomczak-Jaegermann, N., A short proof of Paouris’ inequality. Canad. Math. Bull. 57(1) 2014, 38; MR 3150710.CrossRefGoogle Scholar
Brazitikos, S., Giannopoulos, A., Valettas, P. and Vritsiou, B. H., Geometry of Isotropic Convex Bodies (Mathematical Surveys and Monographs 196 ), American Mathematical Society (Providence, RI, 2014).Google Scholar
Dilworth, S. J. and Montgomery-Smith, S. J., The distribution of vector-valued Rademacher series. Ann. Probab. 21(4) 1993, 20462052; MR 1245300.CrossRefGoogle Scholar
Hitczenko, P., Domination inequality for martingale transforms of a Rademacher sequence. Israel J. Math. 84(1–2) 1993, 161178; MR 1244666.Google Scholar
Kwapień, S. and Woyczyński, W. A., Random Series and Stochastic Integrals: Single and Multiple (Probability and its Applications), Birkhäuser (Boston, MA, 1992); MR 1167198.Google Scholar
Latała, R., Tail and moment estimates for sums of independent random vectors with logarithmically concave tails. Studia Math. 118(3) 1996, 301304; MR 1388035.Google Scholar
Latała, R., Sudakov-type minoration for log-concave vectors. Studia Math. 223(3) 2014, 251274; MR 3274967.Google Scholar
Latała, R. and Strzelecka, M., Weak and strong moments of r -norms of log-concave vectors. Proc. Amer. Math. Soc. 144(8) 2016, 35973608; MR 3503729.Google Scholar
Latała, R. and Tkocz, T., A note on suprema of canonical processes based on random variables with regular moments. Electron. J. Probab. 20(36) 2015, 117; MR 3335827.Google Scholar
Latała, R. and Wojtaszczyk, J. O., On the infimum convolution inequality. Studia Math. 189(2) 2008, 147187; MR 2449135.Google Scholar
Ledoux, M. and Talagrand, M., Probability in Banach Spaces: Isoperimetry and Processes (Classics in Mathematics), Springer (Berlin, 2011); reprint of the 1991 edition; MR 2814399.Google Scholar
Paouris, G., Concentration of mass on convex bodies. Geom. Funct. Anal. 16(5) 2006, 10211049; MR 2276533.Google Scholar
Talagrand, M., Regularity of infinitely divisible processes. Ann. Probab. 21(1) 1993, 362432; MR 1207231.Google Scholar