Hecke-Farey coordinates for Bring's curve that gives Bring's surface

Abstract

The modular group $\Gamma$ (which is the Hecke group $H_3$) can be used to study triangular maps. Here we use the Hecke group $H_4$ to study the regular map that underlies Bring's surface of genus 4. Our main result is the determination of the 20-sided hyperbolic polygon that gives Bring's surface.

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