Computing low-degree isogenies in genus 2 with the Dolgachev–Lehavi method
Computing low-degree isogenies in genus 2 with the Dolgachev–Lehavi method
Let ell be a prime, and H a curve of genus 2 over a field k of characteristic not 2 or ell. If S is a maximal Weil-isotropic subgroup of Jac(H)[ell], then Jac(H)/S is isomorphic to the Jacobian of some (possibly reducible) curve X. We investigate the Dolgachev--Lehavi method for …