Bielliptic modular curves X0⁎(N)

Autor: Francesc Bars, Josep González
Rok vydání: 2020
Předmět:
Zdroj: Journal of Algebra. 559:726-759
ISSN: 0021-8693
DOI: 10.1016/j.jalgebra.2020.02.028
Popis: Let N ≥ 1 be a integer such that the modular curve X 0 ⁎ ( N ) has genus ≥2. We prove that X 0 ⁎ ( N ) is bielliptic exactly for 69 values of N. In particular, we obtain that X 0 ⁎ ( N ) is bielliptic over the base field for all these values of N, except X 0 ⁎ ( 160 ) that is not bielliptic over Q but it does over Q ( − 1 ) . Moreover, we prove that the set of all quadratic points over Q for the modular curve X 0 ⁎ ( N ) is infinite exactly for 100 values of N.
Databáze: OpenAIRE