A sufficient condition for a polyhedron to be rigid
arXiv:1812.06439 · doi:10.1007/s00022-019-0492-0
Abstract
We study oriented connected closed polyhedral surfaces with non-degenerate triangular faces in three-dimensional Euclidean space, calling them polyhedra for short. A polyhedron is called flexible if its spatial shape can be changed continuously by changing its dihedral angles only. We prove that the polyhedron is not flexible if for each of its edges the following holds true: the length of this edge is not a linear combination with rational coefficients of the lengths of the remaining edges. We prove also that if a polyhedron is flexible, then some linear combinations of its dihedral angles remain constant during the flex. In this case, the coefficients of such a linear combination do not alter during the flex, are integers, and do not equal to zero simultaneously.
9 pages
References in corpus (5)
- Flexible cross-polytopes in spaces of constant curvature
- Embedded flexible spherical cross-polytopes with non-constant volumes
- The bellows conjecture for small flexible polyhedra in non-Euclidean spaces
- The analytic continuation of volume and the Bellows conjecture in Lobachevsky spaces
- Dehn invariant of flexible polyhedra