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arXiv · 1205.5077

Computing weight one modular forms over $\C$ and $\Fpbar$

Kevin Buzzard
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Abstract

We report on a systematic computation of weight one cuspidal eigenforms for the group $\Gamma_1(N)$ in characteristic zero and in characteristic $p>2$. Perhaps the most surprising result was the existence of a mod 199 weight~1 cusp form of level 82 which does not lift to characteristic zero.

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Kevin Buzzard. 2012-05-23. Computing weight one modular forms over $\C$ and $\Fpbar$. https://arxiv.org/abs/1205.5077

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