Bielliptic modular curves X0* (N)

Let N ≥ 1 be a integer such that the modular curve X0* (N) has genus ≥ 2. We prove that X0* (N) is bielliptic exactly for 69 values of N. In particular, we obtain that X0* (N) is bielliptic over the base field for all these values of N, except X0*(160) that is not bielliptic over Q but it does over...

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Detalhes bibliográficos
Autores: Bars Cortina, Francesc|||0000-0003-4779-3995; González Rovira, Josep
Tipo de documento: Artigo
Data de publicação:2020
País:España
Recursos:Universitat Autònoma de Barcelona
Repositório:Dipòsit Digital de Documents de la UAB
Idioma:Inglês
OAI Identifier:oai:ddd.uab.cat:240651
Acesso em linha:https://ddd.uab.cat/record/240651
https://dx.doi.org/urn:doi:10.1016/j.jalgebra.2020.02.028
Nível de acesso:Acesso aberto
Palavra-chave:Arithmetic geometry
Hyperelliptic curves
Bielliptic curves
Quadratic points
Elliptic curves
Modular curves
Involutions
Descrição
Resumo:Let N ≥ 1 be a integer such that the modular curve X0* (N) has genus ≥ 2. We prove that X0* (N) is bielliptic exactly for 69 values of N. In particular, we obtain that X0* (N) is bielliptic over the base field for all these values of N, except X0*(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 X0* (N) is infinite exactly for 100 values of N.