Singly-periodic Pointed Pseudotriangulations Have an Expansive Motion
摘要
We show that if a singly-periodic bar-joint framework in the Euclidean plane is derived from a pointed pseudotriangulation on the flexible flat cylinder, then it has a one-parameter deformation, which is expansive, i.e. the motion does not decrease the distance between any pair of joints. For the proof, we consider singly-periodic versions of Maxwell-Cremona liftings and adapt the proof of C. Borcea and I. Streinu for the doubly-periodic version of this statement.