We give an interim report on some improvements and generalizations
of the Abbott–Kedlaya–Roe method to compute the zeta function of a
nondegenerate ample hypersurface in a projectively normal toric variety over
in linear
time in
.
These are illustrated with a number of examples including K3 surfaces, Calabi–Yau
threefolds, and a cubic fourfold. The latter example is a nonspecial cubic fourfold
appearing in the Ranestad–Voisin coplanar divisor on moduli space; this verifies
that the coplanar divisor is not a Noether–Lefschetz divisor in the sense of
Hassett.