Bring's curve

The fundamental polygon for Bring's curve is a regular hyperbolic icosagon (20-gon), shown here with dodecadodecahedral graph in green and its dual in violet. It is a quotient of the order-4 pentagonal tiling and its dual square tiling.
20-gon edges marked with the same letter are equal.
Bring's curve is related to the small stellated dodecahedron and the dodecadodecahedron.[1]

In mathematics, Bring's curve (also called Bring's surface and, by analogy with the Klein quartic, the Bring sextic) is the curve in the projective space cut out by the homogeneous equations

It was named by Klein (2003, p.157) after Erland Samuel Bring who studied a similar construction in 1786 in a Promotionschrift submitted to the University of Lund. Note that the roots xi of the Bring quintic satisfies Bring's curve since for

The automorphism group of the curve is the symmetric group S5 of order 120, given by permutations of the 5 coordinates. This is the largest possible automorphism group of a genus 4 complex curve.

The curve can be realized as a triple cover of the sphere branched in 12 points, and is the Riemann surface associated to the small stellated dodecahedron. It has genus 4. The full group of symmetries (including reflections) is the direct product , which has order 240.

  1. ^ Weber, Matthias (2005). "Kepler's small stellated dodecahedron as a Riemann surface". Pacific J. Math. Vol. 220. pp. 167–182. pdf