On the small ball inequality in three dimensions
Bilyk, Dmitriy ; Lacey, Michael T.
Duke Math. J., Tome 141 (2008) no. 1, p. 81-115 / Harvested from Project Euclid
Let $h_R$ denote an $L^{\infty}$ -normalized Haar function adapted to a dyadic rectangle $R\subset [0,1]^{3}$ . We show that there is a positive $\eta \lt 1/2$ so that for all integers $n$ and coefficients $\alpha (R)$ , we have \[2^{-n} \sum_{|R|=2^{-n}} |{\alpha(R)}| \lesssim n ^{1 - \eta} \|\sum_{|R|=2^{-n}} \alpha(R) h_R \|_\infty . \] This is an improvement over the trivial estimate by an amount of $n ^{-\eta}$ , while the small ball conjecture says that the inequality should hold with $\eta=1/2$ . There is a corresponding lower bound on the $L^{\infty}$ -norm of the discrepancy function of an arbitrary distribution of a finite number of points in the unit cube in three dimensions. The prior result, in dimension three, is that of József Beck [1, Theorem 1.2], in which the improvement over the trivial estimate was logarithmic in $n$ . We find several simplifications and extensions of Beck's argument to prove the result above
Publié le : 2008-05-15
Classification:  42A05,  11K38,  41A46,  42A55,  60E15,  60J65,  60G17
@article{1211574664,
     author = {Bilyk, Dmitriy and Lacey, Michael T.},
     title = {On the small ball inequality in three dimensions},
     journal = {Duke Math. J.},
     volume = {141},
     number = {1},
     year = {2008},
     pages = { 81-115},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1211574664}
}
Bilyk, Dmitriy; Lacey, Michael T. On the small ball inequality in three dimensions. Duke Math. J., Tome 141 (2008) no. 1, pp.  81-115. http://gdmltest.u-ga.fr/item/1211574664/