Unboundedness of the Heesch Number for Hyperbolic Convex Monotiles
A homogeneous (also known as semi-regular) tiling is an edge-to-edge tiling by regular polygons in which every vertex has the same cyclic type. We resolve the Heesch problem in the hyperbolic plane both for such tilings and for convex monotiles, in the latter case without any edge-to-edge restriction. We also construct an infinite family of weakly aperiodic convex monotiles whose interior angles are rational multiples of $\pi$.