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arXiv 0711.4597math.CAmath.CO
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固定距离集、有限域中的Wolff指数及改进的和积估计

Pinned distance sets, Wolff's exponent in finite fields and improved sum-product estimates

Derrick Hart, Alex Iosevich

摘要:

在有限域上的向量空间中的Falconer距离问题的一个类似物要求阈值$α>0$,使得当$|E| \gtrsim q^α$时,$|Δ(E)| \gtrsim q$,其中$E \subset {\Bbb F}_q^d$,有限域上的$d$维向量空间,具有$q$元素(不一定是素数)。这里是$Δ(E)=\{{(x_1-y_1)}^2+...+{(x_d-y_d)}^2: x,y \in E\}$。第二个列出的作者和Misha Rudnev建立了阈值$\frac{d+1}{2}$,本文的作者Doowon Koh和Misha Rudnev证明了这个指数在偶数维中是尖锐的。本文在$E$具有乘积结构的假设下,将阈值改进为$\frac{d^2}{2d-1}$。特别地,我们得到了4/3的指数,与Wolff在欧氏空间中得到的相应指数一致。

英文摘要:

An analog of the Falconer distance problem in vector spaces over finite fields asks for the threshold $α>0$ such that $|Δ(E)| \gtrsim q$ whenever $|E| \gtrsim q^α$, where $E \subset {\Bbb F}_q^d$, the $d$-dimensional vector space over a finite field with $q$ elements (not necessarily prime). Here $Δ(E)=\{{(x_1-y_1)}^2+...+{(x_d-y_d)}^2: x,y \in E\}$. The second listed author and Misha Rudnev established the threshold $\frac{d+1}{2}$, and the authors of this paper, Doowon Koh and Misha Rudnev proved that this exponent is sharp in even dimensions. In this paper we improve the threshold to $\frac{d^2}{2d-1}$ under the additional assumption that $E$ has product structure. In particular, we obtain the exponent 4/3, consistent with the corresponding exponent in Euclidean space obtained by Wolff.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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