Hunter, Cauchy rabbit, and optimal Kakeya sets

Author:

Babichenko Yakov,Peres Yuval,Peretz Ron,Sousi Perla,Winkler Peter

Abstract

A planar set that contains a unit segment in every direction is called a Kakeya set. We relate these sets to a game of pursuit on a cycle Z n \mathbb {Z}_n . A hunter and a rabbit move on the nodes of Z n \mathbb {Z}_n without seeing each other. At each step, the hunter moves to a neighbouring vertex or stays in place, while the rabbit is free to jump to any node. Adler et al. (2003) provide strategies for hunter and rabbit that are optimal up to constant factors and achieve probability of capture in the first n n steps of order 1 / log n 1/\log n . We show these strategies yield a Kakeya set consisting of 4 n 4n triangles with minimal area (up to constant), namely Θ ( 1 / log n ) \Theta (1/\log n) . As far as we know, this is the first non-iterative construction of a boundary-optimal Kakeya set. Considering the continuum analog of the game yields a construction of a random Kakeya set from two independent standard Brownian motions { B ( s ) : s 0 } \{B(s): s \ge 0\} and { W ( s ) : s 0 } \{W(s): s \ge 0\} . Let τ t := min { s 0 : B ( s ) = t } \tau _t:=\min \{s \ge 0: B(s)=t\} . Then X t = W ( τ t ) X_t=W(\tau _t) is a Cauchy process and K := { ( a , X t + a t ) : a , t [ 0 , 1 ] } K:=\{(a,X_t+at) : a,t \in [0,1]\} is a Kakeya set of zero area. The area of the ε \varepsilon -neighbourhood of K K is as small as possible, i.e., almost surely of order Θ ( 1 / | log ε | ) \Theta (1/|\log \varepsilon |) .

Publisher

American Mathematical Society (AMS)

Subject

Applied Mathematics,General Mathematics

Reference12 articles.

1. Randomized pursuit-evasion in graphs;Adler, Micah;Combin. Probab. Comput.,2003

2. Cambridge Tracts in Mathematics;Bertoin, Jean,1996

3. On Kakeya’s problem and a similar one;Besicovitch, A. S.;Math. Z.,1928

4. The Kakeya problem;Besicovitch, A. S.;Amer. Math. Monthly,1963

5. Besicovitch type maximal operators and applications to Fourier analysis;Bourgain, J.;Geom. Funct. Anal.,1991

Cited by 4 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. Almost all non-archimedean Kakeya sets have measure zero;Confluentes Mathematici;2018-09-09

2. Open Problems Column;ACM SIGACT News;2017-12-13

3. Cop vs. Gambler;Discrete Mathematics;2016-06

4. Optimal discrete search with technological choice;Mathematical Methods of Operations Research;2015-04-30

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3