English

Buffon's needle landing near Besicovitch irregular self-similar sets

Analysis of PDEs 2011-01-10 v3 Classical Analysis and ODEs Probability

Abstract

In this paper we get an estimate of Favard length of an arbitrary neighbourhood of an arbitrary self-similar Cantor set. Consider LL closed disjoint discs of radius 1/L1/L inside the unit disc. By using linear maps of smaller disc onto the unit disc we can generate a self-similar Cantor set GG. Then \G=n\Gn\G=\bigcap_n\G_n. One may then ask the rate at which the Favard length - the average over all directions of the length of the orthogonal projection onto a line in that direction - of these sets \Gn\G_n decays to zero as a function of nn. The quantitative results for the Favard length problem were obtained by Peres-Solomyak and Tao; in the latter paper a general way of making a quantitative statement from the Besicovitch theorem is considered. But being rather general, this method does not give a good estimate for self-similar structures such as \Gn\G_n. Indeed, vastly improved estimates have been proven in these cases: in the paper of Nazarov-Peres-Volberg, it was shown that for 1/4 corner Cantor set one has p<1/6p<1/6, such that Fav(\Kn)cpnpFav(\K_n)\leq\frac{c_p}{n^{p}}, and in Laba-Zhai and Bond-Volberg the same type power estimate was proved for the product Cantor sets (with an extra tiling property) and for the Sierpinski gasket SnS_n for some other p>0p>0. In the present work we give an estimate that works for {\it any} Besicovitch set which is self-similar. However estimate is worse than the power one. The power estimate still appears to be related to a certain regularity property of zeros of a corresponding linear combination of exponents (we call this property {\it analytic tiling}).

Keywords

Cite

@article{arxiv.0912.5111,
  title  = {Buffon's needle landing near Besicovitch irregular self-similar sets},
  author = {Matt Bond and Alexander Volberg},
  journal= {arXiv preprint arXiv:0912.5111},
  year   = {2011}
}

Comments

several misprints were corrected, 36 pages