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Transactions of the American Mathematical Society

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Shadows of convex bodies


Author: Keith Ball
Journal: Trans. Amer. Math. Soc. 327 (1991), 891-901
MSC: Primary 52A40; Secondary 52A20
DOI: https://doi.org/10.1090/S0002-9947-1991-1035998-3
MathSciNet review: 1035998
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Abstract: It is proved that if $ C$ is a convex body in $ {\mathbb{R}^n}$ then $ C$ has an affine image $ \tilde C$ (of nonzero volume) so that if $ P$ is any $ 1$-codimensional orthogonal projection,

$\displaystyle \vert P\tilde C\vert \geq \,\vert\tilde C{\vert^{(n - 1)\,/\,n}}.$

It is also shown that there is a pathological body, $ K$, all of whose orthogonal projections have volume about $ \sqrt n $ times as large as $ \vert K{\vert^{(n - 1)\,/\,n}}$.

References [Enhancements On Off] (What's this?)

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DOI: https://doi.org/10.1090/S0002-9947-1991-1035998-3
Article copyright: © Copyright 1991 American Mathematical Society

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