Seamed Riemann Surfaces
Consider a seamed orbifold Riemann surface constructed as follows. Start with the face poset of a three-dimensional cube. Let $\mathcal A_3$ denote the set of antipodal vertex pairs $$a=\{v,v^*\}.$$ To each such pair $a\in\mathcal A_3$, associate a spherical $2$-orbifold $$S^2(\alpha,\alpha)$$ whose two cone points are attached to the antipodal vertices $v$ and $v^*$. Equivalently, and more naturally from the complex-analytic point of view, we regard these spherical orbifolds as copies of $\mathbb{CP}^1$ and glue them along a common seam complex $\Gamma$. Thus the complex foam is $$\mathcal I_{\mathbb C}=\left(\bigsqcup_{a\in\mathcal A_3}^{4}\mathbb{CP}^1_a\right)\big/\!\sim_\Gamma .$$ The cubical scaffold should be understood primarily as an organizational device. Rather than constructing the foam by gluing disks one at a time, as in more traditional constructions of seamed Riemann surfaces or Klein foams, the cube records the incidence structure in advance: whenever two sheets o...