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arXiv · 1403.6254

The automorphism group of the non-split Cartan modular curve of level 11

Valerio Dose·Julio Fernández·Josep González·René Schoof
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Abstract

We derive equations for the modular curve $X_{ns}(11)$ associated to a non-split Cartan subgroup of $\,\mathrm{GL}_2(\mathbf{F}_{11})$. This allows us to compute the automorphism group of the curve and show that it is isomorphic to Klein's four group.

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Valerio Dose, Julio Fernández, Josep González, René Schoof. 2014-03-25. The automorphism group of the non-split Cartan modular curve of level 11. https://doi.org/10.1016/j.jalgebra.2014.05.036

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