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arXiv · 1905.02153

Orthodiagonal anti-involutive Kokotsakis polyhedra

Ivan Erofeev·Grigory Ivanov
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Abstract

We study the properties of Kokotsakis polyhedra of orthodiagonal anti-involutive type. Stachel conjectured that a certain resultant connected to a polynomial system describing flexion of a Kokotsakis polyhedron must be reducible. Izmestiev \cite{izmestiev2016classification} showed that a polyhedron of the orthodiagonal anti-involutive type is the only possible candidate to disprove Stachel's conjecture. We show that the corresponding resultant is reducible, thereby confirming the conjecture. We do it in two ways: by factorization of the corresponding resultant and providing a simple geometric proof. We describe the space of parameters for which such a polyhedron exists and show that this space is non-empty. We show that a Kokotsakis polyhedron of orthodiagonal anti-involutive type is flexible and give explicit parameterizations in elementary functions and in elliptic functions of its flexion.

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Ivan Erofeev, Grigory Ivanov. 2019-05-06. Orthodiagonal anti-involutive Kokotsakis polyhedra. https://arxiv.org/abs/1905.02153

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