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arXiv · 1505.07141

Optimal quotients and surjections of Mordell-Weil groups

Everett W. Howe
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Abstract

Answering a question of Ed Schaefer, we show that if J is the Jacobian of a curve C over a number field, if s is an automorphism of J coming from an automorphism of C, and if u lies in the subring Z[s] of End J and has connected kernel, then it is not necessarily the case that u gives a surjective map from the Mordell-Weil group of J to the Mordell-Weil group of its image.

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Everett W. Howe. 2016-02-10. Optimal quotients and surjections of Mordell-Weil groups. https://doi.org/10.1016/j.jnt.2016.02.013

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