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[几何] 一道复数集合面积的不等式问题

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郝酒 posted 2018-12-3 16:15 |Read mode
令复数集合$A=\{z\in C|\sum_{k=1}^n\frac{1}{|z-k|^{3/2}}\geq1\}$

求证,A的面积$\geq \pi(n^{\frac{4}{3}}-\frac{n^2-1}{12})$.

只会证$n=1$的情形,其余的情形有点复杂呢:)

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Infinity posted 2019-1-30 20:49
这个求和式子让我联想到了偶极子,当n较大时则是多个在一条直线上等间距排列的源和汇(或者从物理角度来说,正电荷和负电荷),然后外轮廓就是某种等势线。

通过mathematica绘图看,这个轮廓线类似于卡西尼卵形线。

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