2022/02/20 by Maxim Arnold, Richard Evan Schwartz, Arnold, Maxim +3 · 1 citation
Computer Science · Engineering · Materials Science · #Advanced Materials and Mechanics #Algebraic Geometry (math.AG) #Digital Image Processing Techniques #Dynamical Systems (math.DS) #FOS: Mathematics #Quasicrystal Structures and Properties
paper · pdf · doi:10.48550/arxiv.2202.09828
openalex publication_date 2022/02/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The evolute of a curve is the envelope of its normals. In this note we consider a projectively natural discrete analog of this construction: we define projective perpendicular bisectors of the sides of a polygon in the projective plane, and study the map that sends a polygon to the new polygon formed by the projective perpendicular bisectors of its sides. We consider this map acting on the moduli space of projective polygons. We analyze the case of pentagons; the moduli space is 2-dimensional in this case. The second iteration of the map has one integral whose level curves are cubic curves, and the transformation on these level curves is conjugated to the map x↦ -4x mod 1. We also present the results of an experimental study in the case of hexagons.