×

Bielliptic modular curves. (English) Zbl 0964.11029

Let \(C\) be a smooth curve of genus at least 2 defined over a number field \(K\). By Falting’s theorem (ex-Mordell conjecture) \(C\) has only finitely many \(K\)-rational points. In order to generalize this result it is considered the set \(\Gamma_d(C,K)=\{P\in C(L) ; [L:K]\leq d\}\) of points of degree at most \(d\) in \(C\). In the case \(d=2\), D. Abramovich and J. Harris, Compos. Math. 78, 227-238 (1991; Zbl 0748.14010)] show that the existence of infinitely many quadratic points is equivalent to \(C\) being hyperelliptic or bielliptic.
In this paper the author considers the family of modular curves \(X_0(N)\) admitting infinitely many quadratic points. This family consists of all hyperelliptic and bielliptic modular curves. Hyperelliptic modular curves were completely determined by the work of [A. Ogg, [Bull. Soc. Math. Fr. 102, 1-61 (1974; Zbl 0314.10018)]. The author completely determines the classification of modular curves \(X_0(N)\) that are bielliptic.

MSC:

11G30 Curves of arbitrary genus or genus \(\ne 1\) over global fields
14G05 Rational points
14H25 Arithmetic ground fields for curves
14K05 Algebraic theory of abelian varieties

Software:

ecdata
Full Text: DOI

References:

[1] Abramovich, D.; Harris, J., Abelian varieties and curves in\(W_d}(C\), Compositio Math., 78, 227-238 (1991) · Zbl 0748.14010
[2] Atkin, A. O.L.; Lehner, J., Hecke operators on \(Γ_0N\), Math. Ann., 185, 134-160 (1970) · Zbl 0177.34901
[3] Cremona, J. E., Algorithms for Modular Elliptic Curves (1992), Cambridge Univ. Press: Cambridge Univ. Press Cambridge · Zbl 0758.14042
[4] Elkies, N., The automorphism group \(X_0\), Compositio Math., 74, 203-208 (1990) · Zbl 0708.14016
[5] Harris, J.; Silvermann, J. H., Bielliptic curves and symmetric products, Proc. Amer. Math. Soc., 112 (1991) · Zbl 0727.11023
[6] Hindry, M., Points quadratiques sur les courbes, C. R. Acad. Sci. Paris, 305, 219-221 (1987) · Zbl 0677.14005
[7] Kenku, M. A.; Momose, F., Automorphism groups of the modular curves \(X_0N\), Compositio Math., 65, 51-80 (1988) · Zbl 0686.14035
[8] Kluit, On the normalizer of \(Γ_0N\); Kluit, On the normalizer of \(Γ_0N\)
[9] Mazur, B.; Swinnerton-Dyer, P., Arithmetic of Weil curves, Invent. Math., 25, 1-61 (1974) · Zbl 0281.14016
[10] Ogg, A. P., Hyperelliptic modular curves, Bull. Soc. Math. France, 102, 449-462 (1974) · Zbl 0314.10018
[11] A. P. Ogg, Rational points on certain elliptic modular curves, Analytic Number Theory, Proceedings of Symposia in Pure Mathematics XXIV, 221, 232; A. P. Ogg, Rational points on certain elliptic modular curves, Analytic Number Theory, Proceedings of Symposia in Pure Mathematics XXIV, 221, 232 · Zbl 0273.14008
[12] Corbes modulars: Taules. Notes del seminari de Teoria de Nombres UB-UAB-UPC, Barcelona, 1992; Corbes modulars: Taules. Notes del seminari de Teoria de Nombres UB-UAB-UPC, Barcelona, 1992
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.