Lattices generated by skeletons of reflexive polytopes

Christian Haase, Benjamin Nill

Published 2005-07-24Version 1

Lattices generated by lattice points in skeletons of reflexive polytopes are essential in determining the fundamental group and integral cohomology of Calabi-Yau hypersurfaces. Here we prove that the lattice generated by all lattice points in a reflexive polytope is already generated by lattice points in codimension two faces. This answers a question of J. Morgan.