On the automorphism group of quotient modular curves

In this article, we determine the automorphism group of all the quotient modular curves of the modular curve X0(pq), where p,q are two distinct primes. In obtaining such results, we provide different insights to compute the automorphism group for any quotient modular curve, which are very effective...

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Detalles Bibliográficos
Autores: Bars, F., Dalal, T.
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2072/484451
Acceso en línea:http://hdl.handle.net/2072/484451
Access Level:acceso abierto
Palabra clave:Atkin-Lehner involution
Automorphism group
Modular curve
Petri's theorem
51
Descripción
Sumario:In this article, we determine the automorphism group of all the quotient modular curves of the modular curve X0(pq), where p,q are two distinct primes. In obtaining such results, we provide different insights to compute the automorphism group for any quotient modular curve, which are very effective when the level of the curve is square-free. In particular, in the case where the level of the quotient curve is non square-free, we would mention that we present an unfamiliar automorphism of order 3 for the genus 4 curve X0⁎(25⋅11) defined over Q[5].