Smooth curves having a large automorphism $p$-group in characteristic $p>0$.
Idioma
en
Article de revue
Este ítem está publicado en
Algebra & Number Theory. 2008, vol. 2, n° 8, p. 887-926
Mathematical Sciences Publishers
Resumen en inglés
Let $k$ be an algebraically closed field of characteristic $p>0$ and $C$ a connected nonsingular projective curve over $k$ with genus $g \geq 2$. This paper continues the work begun by Lehr and Matignon, namely the study ...Leer más >
Let $k$ be an algebraically closed field of characteristic $p>0$ and $C$ a connected nonsingular projective curve over $k$ with genus $g \geq 2$. This paper continues the work begun by Lehr and Matignon, namely the study of "big actions", i.e. the pairs $(C,G)$ where $G$ is a $p$-subgroup of the $k$-automorphism group of $C$ such that$\frac{|G|}{g} >\frac{2\,p}{p-1}$. If $G_2$ denotes the second ramification group of $G$ at the unique ramification point of the cover $C \rightarrow C/G$, we display necessary conditions on $G_2$ for $(C,G)$ to be a big action, which allows us to pursue the classification of big actions. Our main source of examples comes from the construction of curves with many rational points using ray class field theory for global function fields, as initiated by J-P. Serre and followed by Lauter and Auer. In particular, we obtain explicit examples of big actions with $G_2$ abelian of large exponent.< Leer menos
Orígen
Importado de HalCentros de investigación