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arXiv · 1504.07913

The Picard groups of the stacks $Y_0(2)$ and $Y_0(3)$

Andrew Niles
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Abstract

We compute the Picard group of the stack of elliptic curves equipped with a cyclic subgroup of order two, and of the stack of elliptic curves equipped with a cyclic subgroup of order three, over any base scheme on which 6 is invertible. This generalizes a result of Fulton-Olsson, who computed the Picard group of the stack of elliptic curves (with no level structure) over a wide variety of base schemes.

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Andrew Niles. 2015-04-29. The Picard groups of the stacks $Y_0(2)$ and $Y_0(3)$. https://arxiv.org/abs/1504.07913

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