Computing Torsion Points on Curves
Poonen, Bjorn
Experiment. Math., Tome 10 (2001) no. 3, p. 449-466 / Harvested from Project Euclid
Let $X$ be a curve of genus $g \ge 2$ over a field $k$ of characteristic zero. Let $X\box0 A$ be an Albanese map associated to a point $P_0$ on $X$. The Manin--Mumford conjecture, first proved by Raynaud, asserts that the set $T$ of points in $X(\kbar)$ mapping to torsion points on $A$ is finite. Using a $p$-adic approach, we develop an algorithm to compute $T$, and implement it in the case where $k=\funnyQ$, $g=2$, and $P_0$ is a Weierstrass point. Improved bounds on $\#T$ are also proved: for instance, in the context of the previous sentence, if in addition $X$ has good reduction at a prime $p \ge 5$, then $\#T \le\ 2 p^3 + 2 p^2 + 2p + 8$.
Publié le : 2001-05-14
Classification:  torsion packet,  torsion point,  Manin--Mumford conjecture,  Greenberg functor,  Greenberg transform,,  $p$-adic integrals,  hyperelliptic torsion packet,  cuspidal torsion packet,  Kummer surface,  11G30,  14H25,  14K15,  14K20,  11G10
@article{1069786350,
     author = {Poonen, Bjorn},
     title = {Computing Torsion Points on Curves},
     journal = {Experiment. Math.},
     volume = {10},
     number = {3},
     year = {2001},
     pages = { 449-466},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1069786350}
}
Poonen, Bjorn. Computing Torsion Points on Curves. Experiment. Math., Tome 10 (2001) no. 3, pp.  449-466. http://gdmltest.u-ga.fr/item/1069786350/