Abstract
We find infinite families of elliptic curves over quartic number fields with torsion group Z/NZ with N = 20, 24. We prove that for each elliptic curve Et in the constructed families, the Galois group Gal(L/Q) is isomorphic to the Dihedral group D4 of order 8 for the Galois closure L of K over Q, where K is the defining field of (Et, Qt) and Qt is a point of Et of order N. We also notice that the plane model for the modular curve X1(24) found in Jeon et al. (2011) [1] is in the optimal form, which was the missing case in Sutherland's work (Sutherland, 2012 [12]).
Original language | English |
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Pages (from-to) | 115-122 |
Number of pages | 8 |
Journal | Journal of Number Theory |
Volume | 133 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2013 |
Bibliographical note
Funding Information:✩ The first author was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2011-0026917), the second author was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2011-0004284), and the third author was supported by Priority Research Centers Program through the NRF funded by the Ministry of Education, Science and Technology (2010-0028298) and by the NRF grant funded by the Korea government (MEST) (2011-0015684). * Corresponding author. E-mail addresses: [email protected] (D. Jeon), [email protected] (C.H. Kim), [email protected] (Y. Lee).
Keywords
- Dihedral quartic number field
- Elliptic curve
- Modular curve
- Torsion