Surface Quotients of Right-Angled Hyperbolic Buildings

Abstract: Hyperbolic buildings are central objects in both hyperbolic geometry and geometric group theory, exhibiting a wide range of intriguing characteristics, especially with respect to group actions. In this paper, we develop the theory of surface quotients of Fuchsian buildings. For a large family of Fuchsian buildings, we prove the existence of a discrete subgroup $\Gamma$ of the automorphism group of the Fuchsian building whose quotient is a compact surface without boundary. We also provide some necessary conditions for the existence of such lattices, in terms of the symmetries of the building. The proof is based on another result of ours that generators of the fundamental group of a tessellated surface can be chose by closed geodesics in the 1-skeleton of the tessellation, which is of independent interest.