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arXiv math/0504300math.MG
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等径曲线与内接多边形

Curves of constant diameter and inscribed polygons

Mathieu Baillif

摘要:

欧氏平面上的一条简单闭曲线具有性质C_n(R),如果在每一点上都能内接一个唯一的正则$n$ -边形,其边长为$R$ . C_2(R)等价于具有恒定直径。本文证明了对于所有n,除了圆之外,满足C_n(R)的平滑曲线是存在的,并且圆是唯一满足C_2(R)和C_4(R ')的$C^2$正则曲线,其中$R'=R/\sqrt{2}$ .在附录中,我们证明了最后一个断言对任何R和R '都成立。证明只使用了初等微分学和几何。

英文摘要:

A simple closed curve in the Euclidean plane is said to have property C_n(R) if at each point we can inscribe a unique regular $n$-gon with edges length $R$. C_2(R) is equivalent to having constant diameter. We show that smooth curves satisfying C_n(R) other than the circle do exist for all n, and that the circle is the only $C^2$ regular curve satisfying C_2(R) and C_4(R') where $R'=R/\sqrt{2}$. In an addendum, we show that the last assertion holds for any R and R'. The proofs use only elementary differential calculus and geometry.

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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