On oriented planar trees with three leaves
arXiv:2005.05134
Abstract
This elementary note proposes candidates for interesting continuous piecewise-smooth `Riemannian' metrics on the moduli spaces of rooted geodesic trees embedded in the Poincaré disk. A related digression observes the existence of an apparently hitherto unrecognized abelian topological group structure on the real projective line.
Final remark corrected. Comments very welcome