This umbrella was drawn by Maria Vidal for the cover of my thesis and plays with the moduli interpretation of Shimura curves. The head of the umbrella is a representation of a fundamental domain of the Shimura curve of discriminant 6 as appears in Montse Alsina's PhD. Thesis. Over it, curves of genus 2 are raining, some of which are smooth and other are the union of two elliptic curves meeting at a single point. The latter correspond to points with complex multiplication. |