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added a top-level tag; see: https://meta.mathoverflow.net/questions/1457/why-are-mo-tags-formatted-as-they-are
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Martin Sleziak
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fix typos as already bumperd
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Jukka Kohonen
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In two-dimensional case one can generalize figures of constant width as figures which can rotate in a covexconvex polygon. Here is one example which can be used to drill triangular holes:

alt text

I would like to know what happens with this generalization in dimension $3$ and maybe higher. Obviously a body of constant width $1$ can rotate arbitrary in a unit cube. More formally, given a body $B$ of constant width $1$ and $A\in SO(3)$ there is $v\in \mathbb R^3$ such that $$A(B)+v\subset\square,$$ where $\square$ is unit cube. On the other hand, except for the cube, I do not see any other examples of convex polyhedron which have nontrivial rotating bodies (i.e. distinct from the inscribed ball).

I hope that the answer is known. (= I hope I should wait for the answer and I do not have to think.)

The question is inpiredinspired by this one: "Local minimum from directional derivatives in the space of convex bodies."

In two-dimensional case one can generalize figures of constant width as figures which can rotate in a covex polygon. Here is one example which can be used to drill triangular holes:

alt text

I would like to know what happens with this generalization in dimension $3$ and maybe higher. Obviously body of constant width $1$ can rotate arbitrary in a unit cube. More formally, given a body $B$ of constant width $1$ and $A\in SO(3)$ there is $v\in \mathbb R^3$ such that $$A(B)+v\subset\square,$$ where $\square$ is unit cube. On the other hand, except for the cube, I do not see any other examples of convex polyhedron which have nontrivial rotating bodies (i.e. distinct from the inscribed ball).

I hope that the answer is known. (= I hope I should wait for the answer and I do not have to think.)

The question is inpired by this one: "Local minimum from directional derivatives in the space of convex bodies."

In two-dimensional case one can generalize figures of constant width as figures which can rotate in a convex polygon. Here is one example which can be used to drill triangular holes:

alt text

I would like to know what happens with this generalization in dimension $3$ and maybe higher. Obviously a body of constant width $1$ can rotate arbitrary in a unit cube. More formally, given a body $B$ of constant width $1$ and $A\in SO(3)$ there is $v\in \mathbb R^3$ such that $$A(B)+v\subset\square,$$ where $\square$ is unit cube. On the other hand, except for the cube, I do not see any other examples of convex polyhedron which have nontrivial rotating bodies (i.e. distinct from the inscribed ball).

I hope that the answer is known. (= I hope I should wait for the answer and I do not have to think.)

The question is inspired by this one: "Local minimum from directional derivatives in the space of convex bodies."

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Anton Petrunin
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replaced http://mathoverflow.net/ with https://mathoverflow.net/
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replaced http://upload.wikimedia.org/ with https://upload.wikimedia.org/
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Just added the title of the referenced question.; edited body
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Joseph O'Rourke
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Joseph O'Rourke
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Anton Petrunin
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