Rigidity, volume and angle structures of 1-3 type hyperbolic polyhedral 3-manifolds (2501.08081v1)

Abstract: In this paper, we study the rigidity of hyperbolic polyhedral 3-manifolds and the volume optimization program of angle structures. We first study the rigidity of decorated 1-3 type hyperbolic polyhedral metrics on 3-manifolds which are isometric gluing of decorated 1-3 type hyperbolic tetrahedra. Here a 1-3 type hyperbolic tetrahedron is a truncated hyperbolic tetrahedron with one hyperideal vertex and three ideal vertices. A decorated 1-3 type polyhedron is a 1-3 type hyperbolic polyhedron with a horosphere centered at each ideal vertex. We show that a decorated 1-3 type hyperbolic polyhedral metric is determined up to isometry and change of decorations by its curvature. We also prove several results on the volume optimization program of Casson and Rivin, i,e. Casson-Rivin's volume optimization program is shown to be still valid for 1-3 type ideal triangulated 3-manifolds. We also get a strongly 1-efficiency triangulation when assuming the existence of an angle structure. On the whole, we follow the spirit of Luo-Yang's work in 2018 to prove our main results. The main differences come from that the hyperbolic tetrahedra considered here have completely different geometry with those considered in Luo-Yang's work in 2018.