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Coding the real locus of X_0+(N)

Carlos Castano-Bernard
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Abstract

Let X_0+(N) be the Atkin-Lehner quotient of the modular curve X_0(N) associated to the Fricke involution wN. Assume N > 3 prime and endow the real locus X+ 0 (N)(R) with the real topology. In this paper we revisit a special case of result due to Ogg on the connected components of X_0+(N)(R). Then we obtain a formula for the homology class of each connected component of X_0+(N)(R) in terms of Manin symbols.

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Carlos Castano-Bernard. 2006-03-05. Coding the real locus of X_0+(N). https://arxiv.org/abs/math/0603121

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