$X_{\text{ns}}(N)$ is the modular curve $X_H$ for $H\le \GL_2(\widehat\Z)$ the inverse image of a Cartan subgroup of $\GL_2(\Z/N\Z)$ that is nonsplit at every prime dividing $N$.

**Knowl status:**

- Review status: beta
- Last edited by Asimina Hamakiotes on 2024-03-18 19:25:44

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**History:**(expand/hide all)

- 2024-03-18 19:25:44 by Asimina Hamakiotes
- 2023-07-09 09:03:35 by Andrew Sutherland
- 2022-11-06 17:02:55 by Ciaran Schembri

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