Consider a smooth projective curve
over a finite field
,
equipped with a simply branched morphism
of degree
. Assume
if
, and
if
.
In this paper we describe how to efficiently compute a lift of
to characteristic
zero, such that it can be fed as input to Tuitman’s algorithm for computing the Hasse–Weil zeta
function of
.
Our method relies on the parametrizations of low rank rings due to Delone and
Faddeev, and Bhargava.
Keywords
point counting, Tuitman's algorithm, Delone–Faddeev
correspondence, Bhargava correspondence