Consider a curve of genus one over a field K in one of three explicit forms: a double cover of P 1 , a plane cubic, or a space quartic. For each form, a certain syzygy from classical invariant theory gives the curve's jacobian in Weierstrass form and the covering map to its jacobian induced by the K
2-Descent on the Jacobians of Hyperelliptic Curves
โ Scribed by E.F. Schaefer
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 470 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0022-314X
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โฆ Synopsis
Let (J) be the Jacobian of the hyperelliptic curve (Y^{2}=f\left(X^{2}\right)) over a field (K) of characteristic 0 , where (f) has odd degree. We shall present an embedding of the group (J(K) / 2 J(K)) into the group (L^{* / L^{* 2}}) where (L=K[T] / f(T)). Since this embedding is derived from the coboundary map of Galois cohomology, it can be used to compute a 2-descent for the Jacobian. We will use this embedding to compute (J(\mathbf{Q}) 2 J(\mathbf{Q})) for a rank-2 Jacobian of a hyperelliptic curve of genus 3. Academic Press. Inc
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