3 papers
math.CO2026
Rigidity of polytopes with edge length and coplanarity constraints
Matthias Himmelmann, Bernd Schulze, Martin Winter
We investigate a novel setting for polytope rigidity, where a flex must preserve edge lengths and the planarity of faces, but is allowed to change the shapes of faces. For instance…
math.CO2026
Non-Euclidean Crystallographic Rigidity
Jack Esson, Eleftherios Kastis, Bernd Schulze
This paper establishes combinatorial characterisations of forced-symmetric and forced-periodic rigidity (under a fixed lattice) of bar-joint frameworks in non-Euclidean normed plan…
math.CO2025
Orientation-Reversing Crystallographic Rigidity
Jack Esson, Eleftherios Kastis, Bernd Schulze
This paper provides a combinatorial characterisation for generic forced symmetric rigidity of bar-joint frameworks in the Euclidean plane that are symmetric with respect to the ori…